Radiology Review Manual (Dahnert, Radiology Review Manual)

Authors: Dahnert, Wolfgang

Title: Radiology Review Manual, 6th Edition

Copyright 2007 Lippincott Williams & Wilkins

> Table of Contents > Liver, Bile Ducts, Pancreas, and Spleen

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Liver, Bile Ducts, Pancreas, and Spleen

Differential Diagnosis of Hepatic, Biliary, Pancreatic, and Splenic Disorders

Right Upper Quadrant Pain

Liver

Diffuse Liver Disease

Diffuse Hepatic Enlargement = Hepatomegaly

Hepatosplenomegaly

Increased Liver Attenuation

mnemonic: GG CHAT

Generalized Increase In Liver Echogenicity

Marked Decrease in Hepatic T2 Signal Intensity

Liver Mass

Primary Benign Liver Tumor

Primary Malignant Liver Tumor

Solitary Liver Lesion

P.669

SOLITARY ECHOGENIC LIVER MASS

mnemonic: Hyperechoic Focal Masses Affecting the Liver

LIVER MASS SURROUNDED BY ECHOGENIC RIM

Multiple Liver Lesions

BULL's-EYE LESIONS OF LIVER

MILIARY HEPATOSPLENIC LESIONS

Cystic Liver Lesion

FIBROPOLYCYSTIC LIVER DISEASE

Vascular Scar Tumor of Liver

Liver Mass with Capsular Retraction

Low-density Mass in Porta Hepatis

Low-density Hepatic Mass with Enhancement

Fat-containing Liver Mass

Hyperintense Liver Mass on T1WI

Hypervascular Liver Mass

Hepatic Calcification

mnemonic: 4H TAG MAP

Spontaneous Hepatic Hemorrhage

Liver Circulation

Transient Hepatic Parenchymal Enhancement

Arterioportal Shunt

Cause:

Routes:

Pathophysiology:

CECT (in hepatic arterial phase):

Hepatic Artery Enlargement

Dampening of Hepatic Vein Doppler Waveform

Pulsatile Portal Vein

Portal Venous Gas

Etiology:

mnemonic: BE NICE

Pathogenesis:

Composition of colonic gas:

Plain film:

CT:

US:

Doppler:

DDx: pneumobilia (located centrally within bile ducts close to liver hilum + within left lobe of liver)

Gallbladder

Nonvisualization of Gallbladder on OCG

Oral Cholecystogram (OCG)

Dose: 6 0.5 g tablets 2 hours after evening meal

Nonvisualization of Gallbladder on US

Shadowing in Gallbladder Fossa

High-Density Bile

Displaced Gallbladder

Alteration in Gallbladder Size

Enlarged Gallbladder

Small Gallbladder

Gallbladder Wall Thickening

Diffuse Gallbladder Wall Thickening

Focal Gallbladder Wall Thickening

Filling Defects of Gallbladder

Fixed Filling Defects of Gallbladder

mnemonic: PANTS

GALLBLADDER POLYPS

Mobile Intraluminal Mass in Gallbladder

Comet-tail Artifact in Liver and Gallbladder

Echogenic Fat in Hepatoduodenal Ligament

Bile Ducts

Hemobilia

Gas in Biliary Tree = Pneumobilia

mnemonic: I GET UP

Obstructive Jaundice in Adult

Etiology:

Level and cause of obstruction:

Incidence of infected bile in bile duct obstruction:

Organism: E. coli (21%), Klebsiella (21%), enterococci (18%), Proteus (15%)

Test Sensitivity for Common Bile Duct Obstruction:

DDx: Hepatocellular dysfunction (delayed clearance of cardiac blood pool)

Hyperbilirubinemia in Infants

Neonatal Obstructive Jaundice

Jaundice in Older Children

Large Nonobstructed CBD

Filling Defect in Bile Ducts

Echogenic Material in Bile Ducts

Bile Duct Narrowing

Multifocal Intrahepatic Bile Duct Strictures

Papillary Stenosis

Periampullary Tumor

Double-Duct Sign

Congenital Biliary Cysts

Pancreas

Congenital Pancreatic Anomalies

Classification of Congenital Biliary Cysts

P.678

May be associated with: abnormal situs, polysplenia, intestinal malrotation

Pancreatic Calcification

Atrophy of Pancreas

Pancreatic Mass

Pancreatic Neoplasm

Origin: in 99% exocrine ductal epithelium

in 1% acinar portion of pancreatic glands

in 0.1% malignant ampullary tumor with better prognosis

Hypervascular Pancreatic Tumors

Pancreatic Cyst

Unilocular Pancreatic Cyst

Pancreatic Cyst with Solid Component

Macrocystic Lesion of Pancreas

Microcystic Lesion of Pancreas

Hyperamylasemia

Spleen

Nonvisualization of Spleen

Small Spleen

Splenomegaly

Solid Splenic Lesion

Cystic Splenic Lesion

Solitary Splenic Lesion

mnemonic: L'CHAIM

Multiple Splenic Nodules and Masses

Increased Splenic Density

Splenic Calcification

P.682

mnemonic: HITCH

Iron Accumulation in Spleen

Hyperechoic Splenic Spots

Spontaneous Splenic Rupture

P.683

Anatomy of Liver, Bile Ducts, Pancreas, and Spleen

Extrahepatic Portal Vein Tributaries
Variations of Intrahepatic Portal Venous System
Intrahepatic Portal Vein Branches

P.684

Level of Hepatic Vein Junction
Level of Left Portal Vein
Level of Right Portal Vein
Level of Splenic Vein
Functional Segmental Live Anatomy
Goldsmith & Woodburne Couinaud & Bismuth
CAUDATE LOBE Caudate lobe 1
LEFT LOBE Left lateral segment Left lateral superior subsegment 2
Left lateral inferior subsegment 3
Left medial segment Left medial superior subsegment 4a
Left medial inferior subsegment 4b
RIGHT LOBE Right anterior segment Right anterior inferior subsegment 5
Right anterior superior subsegment 8
Right posterior segment Right posterior inferior subsegment 6
Right posterior superior subsegment 7

P.685

Michels Classification of Hepatic Arterial Anatomy

Liver

Functional Segmental Liver Anatomy

Hepatic Arterial Anatomy (Michels classification)

Type 1 (55%):

Type 2 (10%):

Type 3 (11%):

Type 4 (1%):

Type 5 (8%):

Type 6 (7%):

Type 7 (1%):

Type 8 (2%):

Type 9 (4.5%):

Type 10 (0.5%):

Aberrant Hepatic Artery

P.686

Third Inflow to Liver

Effect: focal decrease of portal vein perfusion resulting in areas of fat-sparing/fat accumulation

Hepatic Fissures

Size of Liver

Hepatic Fissures

Liver Echogenicity & Attenuation

US: pancreatic > splenic hepatic > renal echogenicity
CT: 40 70 HU (precontrast)
CECT: early arterial phase (20 sec), late arterial phase (30 40 sec), portal venous phase (60 70 sec); maximal enhancement at 45 60 sec

Maximum Cross-sectional Diameter of Portal Vein

(a) child <10 years of age: 8.5 mm
(b) 10 20 years of age: 10.0 mm
(c) adult: 13.0 mm

P.687

Normal Hemodynamics Parameter of Liver

Portal vein velocity: >11 cm/sec
Congestion index (= cross-sectional area of portal vein divided by average velocity): 0.070 0.09
Hepatic artery resistive index: 0.60 0.64 0.06

Liver Tests

Bile ducts

Normal Size of Bile Ducts

Bile Duct Variants

Prevalence: 2.4% of autopsies;

13 18.5% of operative cholangiograms
Significance: aberrant ducts near cystic duct /gallbladder have the greatest risk of iatrogenic injury at cholecystectomy
Cx: (1) postoperative bile leak if severed

(2) segmental biliary obstruction if ligated
Bile Duct Variants

P.688

Variants of Cystic Duct Insertion

Prevalence: variations occur in 18 23%

Gallbladder

Size & Capacity & Wall Thickness

Length:

(a) infant < 1 year old: 1.5 3 cm in length
(b) older child: 3 7 cm in length
(c) adult: 7-10 cm in length; 2-3.5 cm in width
Capacity: 30-50 mL
Wall thickness: 2-3 mm
Bile volume: 250-1,000 mL/day secreted by hepatocytes
GB function: concentration of bile through absorption of 90% of water

Congenital Gallbladder Anomalies

Agenesis of Gallbladder

Incidence: 0.04-0.07% (autopsy)

Hypoplastic Gallbladder

Septations of Gallbladder

Anatomic Variants of Cystic Duct Insertion

Gallbladder Ectopia

Pancreas

Size

pancreatic head: 1.0 2.2 cm
pancreatic body: 0.4 1.0 cm
pancreatic tail: 0.8 1.8 cm

Physiology of Pancreas

Function: secretion of

Pancreatic Development & Anatomy

Pancreatic Duct Diameters
Embryologic Development of Pancreas

Pancreaticobiliary Junction Variants

Normal Union between CBD & Pancreatic Duct
Variations in Pancreatic Duct Anatomy

Spleen

Size of Spleen

in adults: 12 cm length, 7 8 cm anteroposterior diameter, 3 4 cm thick; splenic index (L W H) of <480
in children: logarithmic increase in length with increasing age; formula for length = 5.7 + 0.31 age (in years)
in infants (0 3 months of age): <6.0 cm in length

Weight of Spleen

at birth: 15 g
in adults: 150 (100 265) g

Embryology of Spleen

P.691

Histology of Spleen

Development: ratio of white to red pulp increases with age + progressive antigenic stimulation

Imaging Characteristics of Spleen

Iron metabolism

Total body iron: 5 g
Absorption: 1-2 mg/day through gut
Transport: bound to transferrin intravascularly

Deposition:

Extraperitoneal Spaces

P.692

Disorders of Liver, Biliary Tract, Pancreas, and Spleen

Accessory Spleen

Incidence: 10 30% of population; multiple (up to 6) in 10%
Cx: disease recurrence due to hypertrophy of accessory spleen after splenectomy for hypersplenism

Ampullary Tumor

Age: 6th + 7th decade; M:F = 2:1
Path: average diameter of <3 cm
Histo: (a) dysplastic epithelium in glandular/villous structures of tubular/villous adenoma

(b) carcinoma in situ

(c) invasive carcinoma often with desmoplastic reaction
Associated with: familial adenomatous polyposis syndromes (eg, familial polyposis coli, Gardner syndrome) [100 200-fold risk], colon carcinoma

TNM staging:

T1: tumor confined to ampulla
T2: tumor extending into duodenal wall
T3: invasion of pancreas <2 cm deep
T4: invasion of pancreas >2 cm deep

International Union Against Cancer Staging:

I = tumor confined to ampulla
II = tumor extension into duodenal wall/pancreas
III = regional lymph node involvement (Lnn stations around head + body of pancreas, anterior + posterior pancreaticoduodenal, pyloric, common bile duct, proximal mesenteric)
IV = invasion of pancreas >2 cm deep
Rx: Whipple procedure (= pancreaticoduodenectomy)
Prognosis: 28 70% 5-year survival for ampullary carcinomas (depending on stage)
DDx:
  1. 1. Periampullary duodenal adenoma/adenocarcinoma (usually larger lesion with significant intraduodenal extension)

  2. Choledochocele (cystic lesion filling with biliary contrast)

  3. Brunner gland tumor, pancreatic rest ( myoepithelial hamartoma ), leiomyoma, carcinoid (often produce somatostatin)

  4. Duodenitis, pancreatitis

  5. 5. Stone impaction in ampulla

Annular Pancreas

Incidence: 1:20,000 autopsies
Age at discovery: childhood (52%); adulthood (48%)
Associated with: other congenital anomalies (in 75%):

esophageal atresia, TE fistula, duodenal atresia/stenosis, duodenal diaphragm, imperforate anus, malrotation, Down syndrome
Location: 2nd portion of duodenum (85%);

1st/3rd portion of duodenum (15%)
neonate: persistent vomiting (duodenal obstruction)
adult: nausea, vomiting (60%), abdominal pain

(70%), hematemesis (10%), jaundice (50%)
Cx: increased incidence of
  1. periampullary peptic ulcers

  2. pancreatitis (15 20%) usually confined to pancreatic head and annulus
Rx: gastrojejunostomy/duodenojejunostomy

Ascariasis

Organism: Ascaris lumbricoides, 25 35 cm long as adult worm; life span of 1 year
Country: 644 million humans harbor the roundworm; 70 90% in America; in United States endemic in: Appalachian range, southern + Gulf coast states
Prevalence: 25% of world population infected

(a) in United States: 12% in blacks, 1% in whites

(b) in parts of Africa, Asia, South America: 90%

Cycle:

Cx:
  1. Intestinal obstruction

  2. Intermittent biliary obstruction with acute cholangitis, cholecystitis, pancreatitis

  3. Liver abscess (rare)

  4. Granulomatous stricture of extrahepatic bile ducts (rare)
Rx: Mebendazole

Autosomal Dominant Polycystic Disease

Associated with: polycystic kidney disease (in 50%)
Cx: infection, compression, bleeding, rupture of cysts

Banti Syndrome

Etiology: increased portal vascular resistance possibly due to portal fibrosis + obliterative venopathy of intrahepatic portal branches
Histo: slight portal fibrosis, dilatation of sinusoids, intimal thickening with eccentric sclerosis of peripheral portal vein walls
Age: middle-aged women; rare in America + Europe but common in India + Japan
Prognosis: 90% 5-year survival; 55% 30-year survival

Biliary Cystadenocarcinoma

Histo: (a) with ovarian stroma (good prognosis), in females only

(b) without ovarian stroma (bad prognosis)
DDx: no image differentiation from biliary cystadenoma

Biliary Cystadenoma

Incidence: 4.6% of all intrahepatic cysts of bile duct origin
Age: >30 years (82%), peak incidence in 5th decade; M:F = 1:4; predominantly Caucasian
Path: multilocular cystic tumor containing proteinaceous fluid with well-defined thick capsule
Histo: single layer of cuboidal/tall columnar biliary-type epithelium with papillary projections, subepithelial stroma resembling that of the ovary

Similar to mucinous cystic tumors of pancreas + ovary
Location: intrahepatic:extrahepatic bile ducts = 85:15;

right lobe (48%); left lobe (20 35%);

both lobes (15 30%); gallbladder (rare)
Cx: (1) malignant transformation into cystadenocarcinoma (indicated by invasion of capsule)

(2) rupture into peritoneum/retroperitoneum
Rx: surgical resection (recurrence common)
DDx: liver abscess, echinococcal cyst, cystic mesenchymal hamartoma (children + young adults), undifferentiated sarcoma (children + young adults), necrotic hepatic metastasis, cystic primary hepatocellular carcinoma

Biliary-Enteric Fistula

Incidence: 5% at cholecystectomy; 0.5% at autopsy
Etiology: cholelithiasis (90%), acute/chronic cholecystitis, biliary tract carcinoma, regional invasive neoplasm, diverticulitis, inflammatory bowel disease, peptic ulcer disease, echinococcal cyst, trauma, congenital communication

Communication with:

DDx: patulous sphincter of Oddi, ascending cholangitis, surgery (choledochoduodenostomy, cholecystojejunostomy, sphincterotomy)

Budd-Chiari Syndrome

Cause:

Pathophysiology: hepatic venous thrombosis leads to elevation of sinusoidal pressure, which causes delayed/reversed portal venous inflow, ascites, alteration in hepatic morphology
Age: all ages; M < F

Location:

Type I : occlusion of IVC hepatic veins
Type II : occlusion of major hepatic veins IVC
Type III : occlusion of small centrilobar veins
Dx: liver biopsy
Rx: control of ascites with diuretics + sodium restriction; anticoagulation, thrombolytic therapy, surgery/balloon dilatation (depending on etiology); transjugular portosystemic shunt; orthotopic liver transplantation (for advanced cases)

Acute Budd-Chiari Syndrome (1/3)

Chronic Budd-Chiari Syndrome (2/3)

Candidiasis Of Liver

P.696

Prevalence: at time of autopsy in 50 70% of acute leukemia, in 50% of lymphoma patients

Most common systemic fungal infection in immunocompromised patients!
Dx: biopsy evidence of yeast/pseudohyphae in central necrotic portion of lesion
DDx: metastases, lymphoma, leukemia, sarcoidosis, septic emboli, other infections (MAI, CMV), Kaposi sarcoma

Caroli Disease

Etiology: (a)? perinatal hepatic artery occlusion

(b)? hypoplasia/aplasia of fibromuscular wall components
Age: childhood + 2nd 3rd decade, occasionally in infancy; M:F = 1:1
Associated with: benign renal tubular ectasia, medullary sponge kidney (in 80%), infantile polycystic kidney disease, choledochal cyst (rare), congenital hepatic fibrosis
Cx: (1) Bile stasis with recurrent cholangitis

(2) Biliary calculi (predominantly bilirubin)

(3) Liver abscess

(4) Septicemia

(5) Increased risk for cholangiocarcinoma (7%)
DDx: polycystic liver disease (noncommunicating), biliary hamartoma (noncommunicating); primary sclerosing cholangitis, recurrent pyogenic cholangitis

Cholangiocarcinoma

Incidence: 0.5 1% of all cancers, 30% of hepatic primary malignancies

Cholangiocarcinomas occur in 10 15% of patients with primary sclerosing cholangitis!

Location:

Path:

Histo: well/moderately/poorly differentiated ductal (most common), papillary, mucinous, signet-ring cell, mucoepidermoid, adenosquamous, cystadenocarcinoma Unusual manifestation:
  1. Mucin-hypersecreting cholangiocarcinoma

    severe diffuse dilatation of intra- and extrahepatic bile ducts proximal + distal to tumor

  2. Squamous cell carcinoma

    = metaplastic transformation of adenocarcinoma cells

Predisposed:

Prognosis: median survival of 7 months, 0 10% 5-year survival

Intrahepatic Cholangiocarcinoma

Incidence: 1/3 of all malignancies originating in the liver; 8 13% of all cholangiocarcinomas; 2nd most common primary hepatic tumor after hepatoma
Histo: adenocarcinoma arising from the epithelium of a small intrahepatic bile duct with prominent desmoplastic reaction (fibrosis); mucin and calcifications
Average age: 50 60 years; M > F
Spread: (a) local extension along duct

(b) local infiltration of liver substance

(c) metastatic spread to regional lymph nodes (in 15%)
Prognosis: <20% resectable; 30% 5-year survival

Klatskin Tumor

Intrahepatic Peripheral Cholangiocarcinoma

Location: right lobe predilection
DDx: metastatic adenocarcinoma/leiomyosarcoma; sclerosing hepatocellular carcinoma

Extrahepatic Cholangiocarcinoma

Age peak: 6th 7th decade, M:F = 3:2
Incidence: <0.5% of autopsies; 90% of all cholangiocarcinomas; more frequent in Far East
Histo: well-differentiated sclerosing adenocarcinoma (2/3), anaplastic carcinoma (11%), cystadenocarcinoma, adenoacanthoma, malignant adenoma, squamous cell = epidermoid carcinoma, leiomyosarcoma
Cx: (1) Obstruction leading to biliary cirrhosis

(2) Hepatomegaly

(3) Intrahepatic abscess (subdiaphragmatic, perihepatic, septicemia)

(4) Biliary peritonitis

(5) Portal vein invasion
Dx: endoscopic brush biopsy (30 85% sensitive)
Prognosis: median survival of 5 months; 1.6% 5-year survival; 39% 5-year survival for carcinoma of papilla of Vater
DDx: sclerosing cholangitis, AIDS cholangitis, benign stricture, chronic pancreatitis, edematous papilla, idiopathic inflammation of CBD

Cholangitis

Acute Obstructive/Ascending Cholangitis

Cause:

Types:

Cx: miliary hepatic abscess formation; secondary sclerosing cholangitis

AIDS-related Cholangitis

Organism: Cryptosporidium (protozoan parasite typically infecting GI tract epithelium), CMV
Histo: marked periductal inflammatory response with interstitial edema + interstitial inflammatory cell infiltrates + necrotic biliary epithelium
Cx: (1) Biliary cirrhosis (up to 49%)

(2) Portal hypertension

(3) Cholangiocarcinoma (clinically in 4 19%; in 7 36% at autopsy/liver transplantation)

(4) Secondary cholangitis
Rx: (1) Palliative: ursodeoxycholic acid, dilatation of dominant strictures

(2) Curative: liver transplantation (4th leading indication)
DDx: (1) Sclerosing cholangiocarcinoma (progressive cholangiographic changes within 0.5 1.5 years of initial diagnosis, marked ductal dilatation upstream from a dominant stricture, intraductal mass >1 cm in diameter)

(2) Acute ascending cholangitis (history)

(3) Primary biliary cirrhosis (disease limited to intrahepatic ducts, strictures less pronounced, pruning + crowding of bile ducts, normal AMA titer)

(4) AIDS cholangiopathy (same on cholangiography)

Recurrent Pyogenic Cholangitis

Etiology: ? Clonorchis sinensis infestation, coliform infection of bile, portal bacteremia, malnutrition
Incidence: 3rd most common cause of an acute abdomen in Hong Kong after appendicitis and perforated ulcer; uncommon in United States
Epidemiology: endemic to Southeast Asia (South China, Indochina, Taiwan, Japan, Korea); Asian immigrants in United States

Associated intrabiliary infestation:

Path: pericholangitis, periductal abscesses, fibrosis of bile duct walls, heavy infiltration of portal tracts by PMNs, intraductal bile pigment calculi
Age: 20 50 years; M:F = 1:1
Location: particularly in lateral segment of L lobe + posterior segment of R lobe
Cx: liver abscess (18%), splenomegaly (14%), biloma (4%), pancreatitis (4%), cholangiocarcinoma (2.5 6%)
Rx: endoscopic sphincterotomy, choledochoduodenostomy
DDx: (1) Caroli disease (saccular dilatation of intrahepatic bile ducts)

(2) Primary sclerosing cholangitis (focal discontinuous bile duct dilatation)

(3) Clonorchiasis (biliary ductal dilatation limited to intrahepatic bile ducts)

Secondary Sclerosing Cholangitis

Cause:

Cholecystitis

Acute Calculous Cholecystitis

Etiology: (a) in 80 95% cystic duct obstruction by impacted calculus; 85% disimpact spontaneously if stone <3 mm

(b) in 10% acalculous cholecystitis
Pathogenesis: chemical irritation from concentrated bile, bacterial infection, reflux of pancreatic secretions
Age peak: 5th 6th decade; M:F = 1:3
Associated with: choledocholithiasis (15 25%)

Oral cholecystography:

P.701

US (81ndash; 100% sensitivity, 60 100% specificity, 92% PPV, 95% NPV):

Color Doppler US:

CECT:

NUC (86 97% sensitivity, 73 100% specificity, 95 98% accuracy):

Endpoint of imaging:

False-positive scans (10 12%) = nonvisualization of GB without acute cholecystitis:

False-negative scans (4.8%) = visualization of GB despite acute cholecystitis:

Cholangiography:

MR cholangiopancreatogram (high sensitivity):

Cx:

mnemonic: GAME BEG

GANGRENE OF GALLBLADDER

Pericholecystic Abscess

Cause: subacute perforation of gallbladder wall subsequent to gangrene + infarction due to acute cholecystitis
Prevalence: 2 20%

Location:

Rx:

Perforation of Gallbladder (in 2 20%)

Location: most commonly at fundus

Empyema of Gallbladder

Acute Acalculous Cholecystitis

Frequency: 5 15% of all acute cholecystitis cases
Associated with: recent surgery in 50%
Etiology: probably caused by decreased blood flow within cystic artery
NUC: same criteria as for calculous cholecystitis
Cx: gallbladder perforation, gangrene, pericholecystic abscess
Rx: percutaneous cholecystostomy trial (low threshold for ICU patients)
Prognosis: 6.5% mortality rate

Chronic Cholecystitis

Emphysematous Cholecystitis

Etiology: small-vessel disease with cystic artery occlusion, complication of acute cholecystitis
Organism: Clostridium perfringens, Clostridium welchii, E. coli, staphylococcus, streptococcus
Age: >50 years; M:F = 5:1
Predisposed: diabetics (20 50%), debilitating diseases; calculous (70 80%)/acalculous cystic duct obstruction
Cx: gangrene (75%); gallbladder perforation (20%)
Mortality: 15%
DDx: (1) Enteric fistula

(2) Incompetent sphincter of Oddi

(3) Air-containing periduodenal abscess

(4) Periappendiceal abscess in malpositioned appendix

(5) Lipomatosis of gallbladder

Xanthogranulomatous Cholecystitis

Incidence: 1 2%
Age: 7th + 8th decade
Histo: mixture of ceroid (waxlike) xanthogranuloma with foamy histiocytes + multinucleated foreign body giant cells + lymphocytes + fibroblasts containing areas of necrosis (in newer lesions)
May be associated with: gallbladder carcinoma (11%)

P.703

DDx: gallbladder carcinoma (in 59% focal, in 41% diffuse thickening of gallbladder wall, multiple masses within liver)
Choledochal Cysts

Choledochal Cyst

Etiology: anomalous junction of pancreatic duct and CBD proximal to duodenal papilla; higher pressure in pancreatic duct and absent ductal sphincter allows free reflux of enzymes into CBD resulting in weakening of CBD wall

Classification:

Kimura type I = pancreatic duct enters the proximal/mid CBD (10 58%) at right angle
Kimura type II = CBD drains into pancreatic duct
Prevalence: 1:13,000 admissions; high prevalence in Japanese/Asian infants
Age: <10 years (60%) + young adulthood; 80% diagnosed in childhood; 7% during pregnancy; occasionally detected up to 8th decade; M:F = 1:4
Histo: fibrous cyst wall without epithelial lining

Associated with:

Cx: (1) Stones in gallbladder, in CBD, within cyst, in intrahepatic biliary tree, in pancreatic duct (8 50%)

(2) Malignant transformation into bile duct carcinoma + gallbladder carcinoma (increasing with age, <1% in 1st decade, 7 14% >age 20)

(3) Recurrent pancreatitis (33%)

(4) Cholangitis/cholecystitis (20%)

(5) Cyst rupture with bile peritonitis (1.8

%) (6) Bleeding

(7) Biliary cirrhosis + portal hypertension

(8) Portal vein thrombosis

(9) hepatic abscess
Rx: excision of cyst + Roux-en-Y hepaticojejunostomy
DDx: mesenteric, omental, ovarian, renal, adrenal, hepatic, enteric duplication cyst, pancreatic pseudocyst, hydronephrotic kidney, hepatic artery aneurysm, biloma (from spontaneous perforation of CBD)

P.704

Choledochocele

Age: 33 years (manifestation usually in adulthood)
Types: (a) CBD terminates in cyst, cyst drains into duodenum (common)

(b) cyst drains into adjacent intramural portion of CBD (less common)
Associated with: stones/sludge (frequent)
Cx: pancreatitis, duodenal obstruction
Rx: sphincterotomy/sphincteroplasty
DDx: choledochal cyst (involves more than only terminal portion of CBD)

Cholelithiasis

Prevalence:

Predisposing factors: female, forty, fair, fat, fertile, flatulent

Pathogenesis:

Composition:

Radiopacity:

Gallstones in Fetus

EGA: >28 weeks EGA
Cause: hemolytic disease, cholestasis, maternal drug use
Prognosis: usually resolve before/after delivery

Gallstones in Neonate

Associated with: obstructive congenital biliary anomaly, total parenteral nutrition, furosemide, GI dysfunction (short-gut syndrome), prolonged fasting, phototherapy, dehydration, infection, hemolytic anemia

Gallstones in Older Children

Associated with: sickle cell disease, cystic fibrosis, malabsorption, total parenteral nutrition, Crohn disease, intestinal resection, hemolytic anemia, choledochal cyst

Cholecystolithiasis

Prognosis: stones <3 mm may pass through cystic duct
Cx: acute cholecystitis (in 30%), choledocholithiasis, cholangitis, pancreatitis, duodenitis, biliary fistula, gallstone ileus, Mirizzi syndrome; cancer of GB + bile ducts (2 3 more frequent)

Cholangiolithiasis

Choledocholithiasis

Etiology: (a) passed stones originating in GB

(b) primary development in intra-/extrahepatic ducts
Incidence: in 12 15% of cholecystectomy patients; in 3 4% of postcholecystectomy patients; in 75% of patients with chronic bile duct obstruction

Stone in Cystic Duct Remnant

Chronic Granulomatous Disease Of Childhood

Etiology: polymorphonuclear leukocyte dysfunction characterized by inability to generate hydrogen peroxide causing prolonged intracellular survival of phagocytized catalase-positive bacteria with dissemination in reticuloendothelial system
Organism: most commonly staphylococcus, Serratia marcescens, Nocardia species, mycobacteria, fungi
Path: chronic infection with granuloma formation/caseation/suppuration
Age: onset in childhood; M > F (more severe in boys)
Rx: prophylactic long-term trimethoprim-sulfamethoxazole + interferon gamma therapy

Cirrhosis

Associated with: anemia, coagulopathy, hypoalbuminemia, cholelithiasis, pancreatitis, peptic ulcer disease, diarrhea, hypogonadism
Cx: (1) Ascites: cause/contributor to death in 50%

(2) Portal hypertension

(3) Hepatocellular carcinoma (in 7 12%)

(4) Cholangiocarcinoma

Fatality from:

Primary Biliary Cirrhosis

Histo: idiopathic progressive destructive cholangitis of interlobar and septal bile ducts, portal fibrosis, nodular regeneration, shrinkage of hepatic parenchyma
Age: 35 55 years; M:F = 1:9

Associated autoimmune disorders:

CT:

NUC:

DDx: (1) Sclerosing cholangitis (young men)

(2) CBD obstruction
Prognosis: mean survival 6 (range 3 11) years after onset of cholestatic symptoms

Complications of End-Stage Liver Disease

Hepatopulmonary Syndrome

Dx: (1) chronic liver disease

(2) increased alveolar-arterial gradient

(3) intrapulmonary vascular dilatation

Hepatic Hydrothorax

Prevalence: 10%
Mechanism: pressure gradient favors fluid movement from peritoneal to pleural cavity through small diaphragmatic defects

Pulmonary Hypertension

Prevalence: 0.73% in patients with liver cirrhosis (versus 0.13% in all patients)

P.709

Prognosis: mean survival of 15 months

Clonorchiasis

Country: endemic to Southeast Asia: Japan, Korea, Central + South China, Taiwan, Indochina
Organism: Chinese liver fluke = Clonorchis sinensis
Cycle: parasite cysts digested by gastric juice, larvae migrate up the bile ducts, remain in small intrahepatic ducts until maturity (10 30 mm in length), travel to larger ducts to deposit eggs
Infection: snail + freshwater fish serve as intermediate hosts; infection occurs by eating raw fish; hog, dog, cat, man are definite hosts
Path: (a) desquamation of epithelial bile duct lining with adenomatous proliferation of ducts + thickening of duct walls (inflammation, necrosis, fibrosis)

(b) bacterial superinfection with formation of liver abscess
Cx: (1) Bile duct obstruction (conglomerate of worms/adenomatous proliferation)

(2) Calculus formation (stasis/dead worms/epithelial debris)

(3) Jaundice in 8% (stone/stricture/tumor)

(4) Generalized dilatation of bile ducts (2%)

Congenital Biliary Atresia

Etiology: ? variation of same infectious process as in neonatal hepatitis with additional component of sclerosing cholangitis or vascular injury
Prevalence: <10 in 100,000 live births
Age: neonate; M:F = 2:1
Histo: periportal fibrosis, proliferation of small intrahepatic bile ducts, mixed inflammatory infiltrates
In 15% associated with: polysplenia, trisomy 18

Types:

I Focal = intrauterine vascular insult (extremely rare)
II Intrahepatic biliary atresia = paucity of intrahepatic bile ducts (uncommon)
III Extrahepatic biliary atresia = atresia of CBD + patent intrahepatic bile ducts
Biliary Atresia

US:

NUC [phenobarbital-augmented cholescintigraphy] (90 97% sensitive, 60 94% specific, 75 90% accurate):

DDx: severe hepatocellular dysfunction (DDx from neonatal hepatitis impossible in the absence of small bowel activity) requires liver biopsy

P.710

MR cholangiography:

Cholangiography (percutaneous/endoscopic/intraoperative) Liver Bx (60 97% accurate)

Rx:
  1. Roux-en-Y choledochojejunostomy (20%);

  2. Kasai procedure = portoenterostomy (80%)
    1. child <60 days of age: 91% success rate

    2. child between 60 and 90 days of age: 50% success rate (due to developing cirrhosis)

    3. child >90 days of age: 17% success rate

  3. Liver transplant

DDx:

Congenital Hepatic Fibrosis

= congenital cirrhosis with rapid + fatal progression

Histo: fibrous tissue within hepatic parenchyma with excess numbers of distorted terminal interlobular bile ducts + cysts that rarely communicate with bile ducts
Age: early childhood 6th decade; majority diagnosed in adolescence/early adulthood

Associated with:

Cx: cirrhosis, portal hypertension, hepatocellular carcinoma, cholangiocellular carcinoma

Echinococcal Disease Of Liver

Echinococcus Granulosus

Cycle: ingestion of contaminated material (eggs passed in feces of dog/other carnivore); eggs hatch in duodenum; larvae penetrate intestinal wall + mesenteric venules; larvae carried into portal circulation; larvae are filtered in capillaries of liver (first line of defense) > lung > other organs

Histo:

Parasitic Cycle Of Echinococcus Granulosus
Time to diagnosis: 11 81 (mean 51) years

Affected organs:

P.711

Location: right lobe > left lobe of liver; multiple cysts in 20%
Size: up to 50 cm (average size of 5 cm), up to 16 liters of fluid; grows 2 3 cm annually

Stages of cyst growth:

Plain film:

US:

CT:

MR:

Angio:

Cholangiography:

Percutaneous aspiration:

Local Cx:

Rx: (1) Surgery (in 10% recurrence)

(2) Anthelmintics (albendazole, medendazole)

(3) Injection of scolecidal agents (silver nitrate, 20/30% hypertonic saline solution,0.5% cetrimide solution, 95% ethanol)

Echinococcus Multilocularis

Primary host: fox, wolf
Secondary host: rodents (moles, lemmings, wild mice); domestic cat; dog
Endemic to: eastern France, southern Germany, western Austria, much of Soviet Union, Japan, Alaska, Canada, some areas in Turkey
Infection: eating wild fruits contaminated with fox/wolf feces; direct contact with fox/wolf; contact with dogs/cats that have ingested infested rodents
Path: larvae proliferate by exogenous extension + penetration of surrounding tissue (= diffuse + infiltrative process resembling malignancy); chronic granulomatous reaction with central necrosis, cavitation, calcification
Histo: daughter cysts with thick lamellar wall arising on outer surface of original cyst, rarely containing scolices
Location: liver (access via portal vein); widespread hematogenous dissemination not uncommon

P.712

US:

CT:

Angio:

Cx: Budd-Chiari syndrome, IVC thrombosis, portal hypertension
Prognosis: fatal within 10 15 years (if left untreated)
DDx: hepatocellular carcinoma (biopsy!), large hemangioma (characteristic enhancement pattern), metastasis, epithelial hemangioendothelioma

Embryonal Rhabdomyosarcoma Of Biliary Tree

rare tumor most commonly arising from CBD

Median age: 3 years; M > F
Path: intraluminal biliary mass/cluster of grapelike masses (similar to rhabdomyosarcoma of bladder)
Histo: same as sarcoma botryoides

Epidermoid Cyst Of Spleen

EPITHELIAL CYST = PRIMARY CYST OF SPLEEN

Incidence: 10% of all benign nonparasitic cysts
Cause: infolding of peritoneal mesothelium/collection of peritoneal mesothelial cells trapped within splenic sulci
Histo: (1) mesothelial lining

(2) squamous epithelial lining = epidermoid cyst = squamous metaplasia from embryonic inclusions within preexisting mesothelial surface epithelium
Age: 2nd 3rd decade (average age of 18 years)
May be associated with: polycystic kidney disease
Cx: trauma, rupture, infection

Eosinophilic Cholangiopathy

rare benign cause of biliary obstruction

Incidence: 15 cases in literature
Cause: unknown
Histo: transmural eosinophilic infiltration of biliary tract
May be associated with: multiple organ involvement (in 50%) of GI tract, urinary tract, bone marrow, pancreas, lymph nodes
Rx: steroids
DDx: lymphoma, AIDS cholangiopathy, collagen vascular disease, cholangiocarcinoma, amyloidosis

Epithelioid Hemangioendothelioma

rare primary malignant vascular tumor of liver (soft tissue, bone, lung)

Age: average age of 45 years; M:F = 1:2
May be associated with: oral contraceptives, exposure to vinyl chloride
Path: multifocal nodules varying in size from a few mm to several cm involve both lobes of the liver (due to rapid perivascular extension); nodules may coalesce in liver periphery
Histo: dendritic spindle-shaped cells + epithelioid round cells in a matrix of myxoid + fibrous stroma; neoplastic endothelial cells invade sinusoids + terminal hepatic + portal veins cutting off the tumor's blood supply
Metastases to: spleen, mesentery, lymph nodes, lung, bone

Plain film:

US:

P.713

CT:

Angio:

NUC:

Prognosis: 20% die within 2 years, 20% survive for 5 28 years treatment
DDx of multiple nodules: metastatic disease
DDx of diffuse form: sclerosing carcinoma, vasoocclusive disease

Fatty Liver

FATTY INFILTRATION OF THE LIVER = HEPATIC STEATOSIS

Cause:

Histo: hepatocytes with large cytoplasmic fat vacuoles containing triglycerides; >5% fat of total liver weight

Diffuse fatty infiltration

Fat-Spared Area in diffuse fatty infiltration

Cause: direct drainage of systemic blood into liver

Location:

DDx: tumor mass

Focal Fatty Infiltration

Etiology: ? vascular origin, focal tissue hypoxia
Distribution: (a) lobar/segmental uniform lesions

(b) lobar/segmental nodular lesions

(c) perihilar lesions

(d) diffuse nodular lesions

(e) diffuse patchy lesions

predominantly in centrilobar + periportal regions, subcapsular distribution may be due to variants of blood supply (due to third inflow from connection between peripheral portal radicles + perforating capsular/accessory cystic veins)
Location: right lobe, caudate lobe, perihilar region
DDx: primary/secondary hepatic tumor

Focal Nodular Hyperplasia

FNH = rare benign congenital hamartomatous malformation or reparative process in areas of focal injury; SPECIFIC DIAGNOSIS RARELY POSSIBLE

P.714

Prevalence: 0.9%; 2nd most common benign tumor of liver after hemangioma; 3 8% of all primary hepatic tumors in adult population, 4% in pediatric population; twice as common as hepatocellular adenoma
Cause: (?) congenital arteriovenous malformation triggers focal hepatocellular hyperplasia owing to a regional increase in blood flow

Oral contraceptives DO NOT cause FNH, but exert a trophic effect on its growth!
Path: localized, well-delineated, usually solitary (80 95%), subcapsular mass composed of numerous small nodules within an otherwise normal liver; no true capsule; frequently central fibrous scar in area of interconnection of fibrous bands (HALLMARK); angioarchitecture typically has one/more thick-walled arteries within fibrous septa dividing into numerous capillaries connected to sinusoids, which are drained by large hepatic veins (no portal veins!); FNH hepatocytes contain steatosis in 50%
Histo: composed of multiple spherical aggregates of hepatocytes often containing increased amounts of fat (in 50%) + triglycerides + glycogen; Kupffer cells line sinusoids; bile duct proliferation within fibrous septa without connection to biliary tree; thick-walled arteries within fibrous septa radiating from the center toward the periphery; absent portal triads + central veins; difficult differentiation from regenerative nodules of cirrhosis + hepatocellular adenoma

Pathologic classification:

Age peak: 3rd 4th decade (range: 7 months to 75 years);

M:F = 1:8
Associated with: hepatic hemangioma (in 23%), meningioma, astrocytoma, arterial dysplasia of other organs in case of multiple FNH
Location: right lobe:left lobe = 2:1; multiple in 20%
Size: <5 cm (in 85%)

NECT:

CECT (3 phases necessary!):

US:

Doppler:

MR (70% sensitive, 98% specific, requires 3 phases):

CEMR (2-D/3-D GRE):

NUC:

Tc-HIDA:

Tc-99m tagged RBCs:

Angio:

Rx: (1) Discontinuation of oral contraceptives

(2) Resection of pedunculated mass

(3) Diagnostic excisional biopsy for extensive tumor (FNH seldom requires surgery)
Cx: rarely rupture with hemoperitoneum (increased incidence in patients on oral contraceptives 14%)

DDx:

Telangiectatic Focal Nodular Hyperplasia

Frequency: 10% of all FNH
Age: mean age 38 years; women
Associated with: oral contraceptives (mean time, 15 years)
Mean size: 7 cm

MR:

DDx: hepatic adenoma

Gallbladder Carcinoma

Incidence: 0.4 4.6% of biliary tract operations; most common biliary cancer (9 more common than extrahepatic bile duct cancer); 6th most common gastrointestinal malignancy (after colon, pancreas, stomach, liver, esophagus); 3% of all intestinal neoplasms; 7,000 new cases/year in United States
Demographics: most common in Israel, Bolivia, Chile, northern Japan, New Mexico
Ethnicity: Native Americans + Hispanic Americans (associated with increased prevalence of gallstones)
Median age: 72 years; M:F = 1:3 1:4; whites > blacks

85% occur in 6th decade or later!
Risk factors: increased body mass, female gender, postmenopausal status, cigarette smoking, chronic Salmonella typhi infection, exposure to chemicals (rubber, automobile, wood finishing, metal fabricating industries)

Associated with:

Path: diffusely infiltrating lesion (68%), intraluminal polypoid growth (32%)
Histo:
  1. (a) adenocarcinoma (76%):

    papillary (6% with tendency to fill gallbladder lumen)

    intestinal type (variant of well-differentiated adenocarcinoma with intestinal glands)

    mucinous (5%, with >50% extracellular mucin)

    signet-ring cell (abundant intracytoplasmic mucin)

    clear cell (well-defined cytoplasmic borders)

  2. (b) rare epithelial cell types:

    adenosquamous carcinoma (3%)

    squamous cell carcinoma (1%)

    small (oat) cell carcinoma (0.5%, highly aggressive, paraneoplastic Cushing syndrome)

    undifferentiated carcinoma

  3. (c) nonepithelial cell types (2%):

    carcinoid, carcinosarcoma, basal cell carcinoma, lymphoma

P.716

Modified Nevin Stage:

I mucosa only (in situ carcinoma)
II mucosal + muscular invasion
III mucosa + muscularis + serosa
IV gallbladder wall + lymph nodes
V hepatic/distant metastases
Location: fundus (60%), body (30%), neck (10%)

Growth types:

N.B.: misdiagnosis by US/CT in 50%, especially in the presence of gallstones

Abdominal radiograph:

Cholangiography:

US:

CT:

MR:

Metastases: in 75 77% at time of diagnosis
Cx: perforation of gallbladder + abscess formation

gallstones located within abscess
Prognosis: 75% unresectable at presentation; average survival is 6 months; 5% 1-year survival rate; 6% 5-year survival rate
DDx: (1) Xanthogranulomatous cholecystitis (lobulated mass filling gallbladder + stones)

(2) Acute/chronic cholecystitis (generalized gallbladder wall thickening <10 mm)

(3) Liver tumor invading gallbladder fossa

(4) Tumors from adjacent organs (pancreas, duodenum)

(5) Metastases (melanoma, leukemia, lymphoma)

(6) Polyps: cholesterol polyp, hyperplastic polyp, granulation polyp

(7) Adenomyomatosis

Glycogen Storage Disease

Von Gierke Disease (Type I)

Etiology: defect in glucose-6-phosphatase with excess deposition of glycogen in liver, kidney, intestines
Dx: failure of rise in blood glucose after glucagon administration
Age at presentation: infancy
Prognosis: death in infancy, may survive into adulthood with early therapy
Cx: (1) Hepatic adenoma

(2) Hepatocellular carcinoma

P.717

Pompe Disease (Type II)

Etiology: defect in lysosomal glucosidase
Prognosis: sudden death in 1st year of life (due to conduction abnormalities); survival rarely beyond infancy

Cori Disease (Type III)

Andersen Disease (Type IV)

McArdle Disease (Type V)

Hers Disease (Type VI)

Hemochromatosis

excess iron deposition in various parenchymal organs (liver, pancreas, spleen, kidneys, heart) leading to cirrhosis with portal hypertension

Cause: excess iron deposition from

  1. increased GI absorption:
    1. Genetic hemochromatosis

    2. Erythropoietic hemochromatosis

    3. Bantu siderosis

  2. IV blood transfusion

  3. intravascular (extrasplenic) hemolysis

CT (60% sensitivity for iron):

Genetic Hemochromatosis

Cause: autosomal recessive disorder (abnormal HFE gene located near human-leukocyte antigen [HLA] on short arm of chromosome 6) with increased absorption of intestinal iron
Prevalence: 1:220 whites of northern European ancestry; homozygote frequency up to 0.25 0.50%; heterozygote carriers >10%

Pathophysiology:

Path: excess iron stored as crystalline iron oxide (ferric oxyhydroxide) within cytoplasmic ferritin + lysosomal hemosiderin; iron overload affects parenchymal cells (liver, pancreas, heart) NOT Kupffer cells/RE cells of bone marrow + spleen (abnormal function of RES)
Age: after middle age; female iron loss during menses and pregnancy provides some protection

MR:(skeletal muscle = good signal intensity reference)

Dx: liver biopsy
Cx: (1) Periportal fibrosis resulting in cirrhosis (if iron concentration >22,000 g/g of liver tissue)

(2) Hepatocellular carcinoma (14 30%)

(3) Insulin-dependent diabetes mellitus (30 60%)

(4) Congestive cardiomyopathy (15%)
Rx: phlebotomies in precirrhotic stage
Prognosis: normal life expectancy with early diagnosis and treatment

Secondary Hemochromatosis

Path: iron deposition initially in RES (phagocytosis of intact RBC) with sparing of parenchymal cells of pancreas; after saturation of RES storage capacity parenchymal cells of other organs accumulate iron (liver, pancreas, myocardium)
Age: 4th 5th decade; M:F = 10:1

P.718

MR:

Transfusional Siderosis

Rx: iron chelation therapy to remove excess iron

Hepatic Abscess

Types: pyogenic (85%), fungal (9%), amebic (6%)
Location: multiple in 50% A pyogenic abscess tends to be centrally located, an amebic abscess peripherally!

MR:

Amebic Abscess

Organism: Entamoeba histolytica
Etiology: spread of viable amebae from colon to liver via portal system
Incidence: in 1 25% of intestinal amebiasis
Age: 3rd 5th decade; M:F = 4:1
Location: liver abscess (right lobe) in 2 25%; systemic dissemination by invasion of lymphatics/portal system (rare); liver:lung:brain = 100:10:1
Size: 2 12 cm; multiple liver abscesses in 25%

CT:

US:

NUC:

Aspiration:

Cx: (1) Diaphragmatic disruption (rare) is strongly suggestive of amebic abscess

(2) Fistulization into colon, right adrenal gland, bile ducts, pericardium
Rx: conservative treatment with chloroquine/metronidazole (Flagyl ); percutaneous drainage for left hepatic abscess (spontaneous rupture into pericardium + tamponade possible)
Prognosis: resolution under therapy may take from 1 month to 2 years; permanent cysts may remain behind

Pyogenic Liver Abscess

Organism: E. coli, aerobic streptococci, St. aureus, anaerobic bacteria (45%); polymicrobial (>50%)
Incidence: 0.016%
Predisposed: steroids, immunosuppressed state, excessive antibiotics usage

Etiology:

Age: 6th 7th decade; M > F
Location: solitary abscess in right lobe (40 75%), in left lobe (2 10%); multiple abscesses in 10 34 73% (more often of biliary than hematogenous origin)

US:

CT:

MR:

NUC:

Cx: (1) Septicemia

(2) Rupture into right subphrenic space

(3) Rupture into abdominal cavity

(4) Rupture into pericardium

(5) Empyema

(6) Common hepatic duct obstruction
Mortality: 20 80%; 100% if unrecognized/untreated

Hepatic Adenoma

Prevalence: half as common as FNH
Path: pseudocapsule due to compression of liver tissue containing multiple large vessels; high incidence of hemorrhage + necrosis + fatty change; no scar
Histo: solitary spherical benign growth of hepatocytes; sheets of hepatocytes; sheets of hepatocytes without portal veins or central veins; scattered thin-walled vascular channels + bile canaliculi; decrease in number of abnormally functioning Kupffer cells; hepatocytes contain increased amounts of glycogen fat
Age: young women in childbearing age; not seen in males unless on anabolic steroids; rare in children

Associated with:

Location: right lobe of liver in subcapsular location (75%); multiple in 20 30% (eg, hepatic adenomatosis without risk factors)
Size: between 6 and 30 cm in size (average size of 8 10 cm)

CT:

CECT:

US:

MR:

NUC:

P.720

Angio:

CAVE: percutaneous biopsy carries high risk of bleeding!
Cx: (1) Spontaneous hemorrhage with subcapsular hematoma/hemoperitoneum (41%)

(2) Malignant transformation (? contiguous development of hepatocellular carcinoma)

(3) Recurrence after resection
Rx: hormone therapy stopped; screening for malignant degeneration with -fetoprotein; surgical resection (to prevent rupture)
DDx: FNH, hemangioma, fibrolamellar hepatocellular carcinoma; metastasis

Hepatic Angiomyolipoma

rare benign mesenchymal tumor

Associated with: tuberous sclerosis
Histo: smooth muscle cells, fat, proliferating blood vessels
Cx: intratumoral hemorrhage

Hepatic Angiosarcoma

HEMANGIOENDOTHELIAL SARCOMA = KUPFFER CELL SARCOMA = HEMANGIOSARCOMA

Prevalence: 0.14 0.25 per million; <2% of all primary liver neoplasms; most common sarcoma of liver (followed by fibrosarcoma > malignant fibrohistiocytoma > leiomyosarcoma)

Etiology:

Associated with: hemochromatosis, anabolic steroids, cirrhosis, von Recklinghausen disease

Path:

Histo:

Age: 6th 7th decade; M:F = 4:1

Early metastases to:

Plain film:

NUC:

US:

CT:

MR:

Angio:

CAVE: Biopsy may lead to massive bleeding in 16%! Have surgical backup available!
Prognosis: rapid deterioration with median survival of 6 months (13 months under chemotherapy)
DDx for multiple lesions: hypervascular metastases
DDx for single lesion: cavernous hemangioma, HCC (no splenic metastases)

Hepatic Cyst

Prevalence: 2 7%; increasing with age; M < F

P.721

Size of cyst: range from microscopic to huge (average 1.2 cm; in 25% largest cyst <1 cm; in 40% largest cyst >4 cm; maximal size of 20 cm)
Number of cysts: multiple cysts spread throughout liver (in 60%)/solitary cyst
Rx: sclerosing therapy with minocycline hydrochloride (Dose: 1 mg per 1-mL cyst content up to 500 mg in 10 mL of 0.9% saline + 10 mL 1% lidocaine) following contrast opacification of cyst to confirm absence of communication with biliary tree/leakage into peritoneal cavity

Hepatic Hemangioma

Cavernous Hemangioma of Liver

Incidence: 1 4%; autopsy incidence 0.4 7.3%; increased with multiparity
Cause: ? enlarging hamartoma present since birth,? true vascular neoplasm
Age: rarely seen in young children; M:F = 1:5
Path: large vascular channels filled with slowly circulating blood; lined by single layer of mature flattened endothelial cells separated by thin fibrous septa; no bile ducts; thrombosis of vascular channels common resulting in fibrosis + hemorrhage + myxomatous degeneration + calcifications
Pathophysiology: large blood volume with low blood flow
Associated with: (1) Hemangiomas in other organs

(2) Focal nodular hyperplasia

(3) Rendu-Osler-Weber disease
Location: frequently peripheral/subcapsular in posterior right lobe of liver; 20% are pedunculated; multiple in 10 20%
Size: <4 cm (90%); >4 6 12 cm = giant cavernous hemangioma

US:

CT (combination of precontrast images, good bolus, dynamic scanning):

MR (90 95% accuracy):

Angio (historical gold standard):

NUC (95% accuracy with SPECT):

Indication: lesions >2 cm (detectable in 70 90%)
Bx: may be biopsied safely provided normal liver is present between tumor + liver capsule

nonpulsatile blood (73%)

endothelial cells without malignancy (27%)
Prognosis: no growth when <4 cm in diameter; giant cavernous hemangiomas may enlarge
Cx (rare): (1) Spontaneous rupture (4.5%)

(2) Abscess formation

(3) Kasabach-Merritt syndrome (platelet sequestration)
DDx: hypervascular malignant neoplasm/metastasis (quick homogeneous filling during arterial phase of small hemangiomas)

P.722

Giant Hepatic Cavernous Hemangioma

Associated with: coexistent smaller <5 cm hemangioma in 13%
Histo: hemorrhage, thrombosis, extensive hyalinization, liquefaction, fibrosis; central cleft due to cystic degeneration/liquefaction

US:

NECT:

CECT:

MR:

CEMR:

DDx: metastasis, hepatocellular carcinoma, cholangiocarcinoma, hepatic adenoma, FNH (smaller and less hyperintense central scar on T2WI), focal fatty infiltration

Infantile Hemangioendothelioma of Liver

Histo: multiple anastomosing thick-walled vascular spaces similar to cavernous hemangioma lined by plump immature endothelial cells in single or (less often) multiple cell layers; areas of extramedullary hematopoiesis/thrombi; scattered bile ducts; involutional changes (infarction, hemorrhage, necrosis, scarring)

Classification:

Age at presentation: <6 months in 85%, during 1st month in 33%, >1 year in 5%; M: F = 1:1.4-1:2
Size: several mm up to 20 cm (average size of 3 cm)

Plain film:

US:

OB-US:

NECT:

CECT (similar to cavernous hemangioma):

MR:

NUC (sulfur colloid, tagged RBC):

Angio:

Prognosis: rapid growth in first 6 months followed by tendency to involute within 6 8 months; 32 75% survival rate in complicated cases
Cx: (1) Congestive heart failure

(2) Hemorrhagic diathesis

(3) Obstructive jaundice

(4) Hemoperitoneum (rupture of tumor) (5) Malignant transformation into angiosarcoma (rare)
Rx: (1) No treatment if asymptomatic

(2) Reduction in size with steroids/radiotherapy/chemotherapy

(3) Embolization(4) Surgical resection/liver transplantation
DDx: (1) Hepatoblastoma (>1 year of age, elevated -fetoprotein, more heterogeneous)

(2) Mesenchymal hamartoma (usually multilocular cystic mass) (3) Metastatic neuroblastoma (elevated catecholamines in urine, adrenal mass, nonenhancing multiple liver masses)

Hepatic Venoocclusive Disease

Etiology: radiation and chemotherapy in bone-marrow transplant patients; bush tea (alkaloid) consumption in Jamaica

Hepatitis

Cause: alcohol, medication, viral infection, NASH (nonalcoholic steatohepatitis)

Acute Hepatitis

CT:

US:

Chronic Hepatitis

Cause: autoimmune hepatitis; hepatitis B, C, D; cryptic hepatitis; chronic drug hepatitis; primary biliary cirrhosis; primary sclerosing cholangitis; Wilson disease; alpha-1 antitrypsin deficiency

US:

Cx: cirrhosis (10% for hepatitis B; 20 50% for hepatitis C)

Neonatal Hepatitis

Cause:

Age: 1 4 weeks of age; M > F
Histo: multinucleated giant cells with hepatic parenchymal disruption, relatively little bile within bile duct canaliculi

US:

NUC:

Technique: often performed after pretreatment with phenobarbital (5 mg/kg 5 days) to maximize hepatic function
Prognosis: spontaneous remission
DDx: biliary atresia (NO small bowel activity)

Radiation Hepatitis

Acute Radiation-induced Hepatitis

Time of onset: 2 6 weeks after completion of radiation therapy with dose >3,500 rad (35 Gy)
Prognosis: complete recovery in majority

Chronic Radiation-induced Hepatitis

Viral Markers of Hepatitis
Virus Tests Interpretation
HAV Anti-HAV IgM acute hepatitis (can remain positive for >1 year)
Anti-HAV IgG past hepatitis, lifelong immunity
HBV HBsAg acute/chronic disease
Anti-HBc IgM acute infection (if titer high); chronic infection (if titer low)
Anti-HBc IgG past/recent HBV contact (may be only serum indicator of past infection)
HBe active viral replication
Anti-HBe low/absent replicative state (typically present in long-standing HBV carriers)
Anti-HBs immunity after vaccination
HBV-DNA active viral replication
HCV Anti-HCV past/current infection
RIBA test for various viral components
HCV-RNA active viral replication
HDV Anti-HDV IgM acute/chronic infection
Anti-HDV IgG chronic infection (if titer high + IgM positive); past infection if titer low + IgM negative)
HDV-RNA active viral replication
HEV Anti-HEV IgM acute hepatitis
Anti-HEV IgG past hepatitis
HEV-RNA viral replication

Hepatoblastoma

Incidence: 3rd most common abdominal tumor in children; most frequent malignant hepatic tumor in infants + children <3 years of age
Incidence increased with: hemihypertrophy, Beckwith syndrome

Histo:

Age: <3 years; <18 months (in 50%); peak age between 18 and 24 months; range from newborn to 15 years; M:F = 2:1
Metastases to: lung (frequent)
Location: right lobe of the liver

US:

CT:

MR:

NUC:

Angio:

Prognosis: 60% resectable; 75% mortality; better prognosis than hepatoma; better prognosis for epithelial type than mixed type
DDx: hemangioendothelioma (fine granular calcifications), metastatic neuroblastoma, mesenchymal hamartoma, hepatocellular carcinoma (>5 years of age, no calcifications)

Hepatocellular Carcinoma

Incidence: (a) in industrialized world: 0.2 0.8%

(b) in sub-Saharan Africa, Southeast Asia, Japan, Greece, Italy: 5.5 20%
Peak age: (a) industrialized world: 6th 7th decade; M:F = 2.5:1; fibrolamellar subtype (in 3 10%) below age 40 years

(b) high incidence areas: 30 40 years; M:F = 5:1

(c) in children: >5 years of age (peak at 12 14 years); M:F = 4:3

P.725

Etiology:

mnemonic: WHAT causes HCC?
Path: soft tumor due to lack of stroma, often hemorrhagic + necrotic
Histo: HCC cells resemble hepatocytes in appearance + structural pattern (trabecular, pseudoglandular = acinar, compact, scirrhous);

(a) expansive encapsulated HCC: collapsed portal vein branches at capsule

(b) infiltrative nonencapsulated HCC: portal venules communicate with tumoral sinusoids = often invasion of portal hepatic veins

Growth pattern:

Vascular supply: hepatic artery, portal vein in 6%
Metastases to: lung (most common = 8%), adrenal, lymph nodes, bone

CT (sensitivity of 63% in cirrhosis, 80% without cirrhosis):

False-positive: confluent fibrosis, regenerative nodule

Biphasic CECT:

CT with intraarterial ethiodol injection:

US:

MR:

CEMR:

NUC:

Angio:

Prognosis: >90% overall mortality; 17% resectability rate; 6 months average survival time; 30% 5-year survival time
Cx: spontaneous rupture (in 8%)
Rx: (1) Resection

(2) I-131 antiferritin IgG (remission rate >40% up to 3 years)
DDx: hepatocarcinoma, cholangiocarcinoma, focal nodular hyperplasia, hemangioma, hepatic adenoma

Fibrolamellar Carcinoma of Liver

Prevalence: 1-9% of all HCCs; up to 35% of hCCs in patients <50 years of age
Age: 5-69 (mean 23) years; mostly 2nd-3rd decade; M:F = 1:1
Path: large well-circumscribed lobulated nonencapsulated strikingly desmoplastic tumor with calcifications + fibrous central scar
Histo: large hepatocyte-like cells with granular eosinophilic cytoplasm growing in sheets/cords/trabeculae separated by broad bands of fibrous stroma arranged in parallel lamellae resulting in compartmentalized appearance
Risk factors: NONE known; underlying cirrhosis or hepatitis in <5%
Demographics: less common in Europe; rare in Japan + China

US:

CT:

MRI:

Angio:

NUC:

Prognosis: 48% resectability rate; 32 months average survival time; 67% 5-year survival time
DDx: focal nodular hyperplasia (young + middle-aged women, <5 cm in size, calcifications uncommon, isointense to liver on all CT + MR images with pronounced homogeneous enhancement during arterial phase, hyperintense central scar on T2WI, uptake of sulfur colloid/super paramagnetic iron oxide)

Hyperplastic Cholecystosis

Incidence: 30 50% of all cholecystectomy specimens; M:F = 1:6

Adenomyomatosis of Gallbladder

Histo: hyperplasia of epithelial + muscular elements with mucosal outpouching of epithelium-lined cystic spaces into (46%) or all the way through (30%) a thickened muscular layer as tubules/crypts/2 8 mm saccules (= intramural diverticula = Rokitansky-Aschoff sinus); develop with increasing age

[Karl Rokitansky (1804 1878), pathologist in Vienna, Austria]

[Carl Aschoff (1866 1942), pathologist in Bonn, Germany]
Incidence: 2 5% of all cholecystectomy specimens
Age: >35 years; M:F = 1:3
Associated with: (1) Gallstones in 25 75%

(2) Cholesterolosis in 33%

P.727

Types:

DDx: gallbladder carcinoma

Cholesterolosis

Strawberry Gallbladder

Associated with: cholesterol stones in 50 70%

Cholesterol Polyp (90%)

Prevalence: 4%; most common (50%) fixed filling defect of gallbladder
Age: 40 50 years; M:F=1:3
Location: commonly in middle 1/3 of gallbladder
DDx: papilloma, adenoma, inflammatory granuloma

Inspissated Bile Syndrome

Associated with: massive hemolysis (Rh incompatibility), hemorrhage (intraabdominal, intracranial, retroperitoneal), increased enterohepatic circulation (Hirschsprung disease, intestinal atresia, stenosis)

US:

Intraductal Papillary Mucinous Tumor Of Pancreas

Path: conglomeration of communicating cysts covered by a rim of normal pancreatic parenchyma + thin fibrous capsule
Histo: cysts represent a dilated duct lined with innumerable papillae coated with hyperplastic/atypical/malignant epithelium (adenoma-carcinoma sequence)
Age: elderly patients; M>F
Prognosis: low-grade malignancy with better prognosis than pancreatic adenocarcinoma
Dx: ERCP (bulging ampulla, mucin pouring from papilla, communication between pancreatic duct + cystic cavity)
Rx: Whipple operation (main duct IPMT/partial pancreatectomy (branch duct IPMT)
DDx: chronic obstructive pancreatitis, serous/mucinous cystic tumors, pseudocyst

Main Duct IPMT

Age: 57 (range, 34 75) years; M:F = 1:1
DDx: peripheral mucinous cystic tumor (main duct almost always normal)

P.728

ERCP:

N.B.: reflux of contrast material due to excess of mucin/patent papillary orifice hinders filling of ductal tree

Branch Duct IPMT

Age: 63 (range, 37 76) years; M:F=1:1
Location: mainly in uncinate process >> pancreatic tail > pancreatic body
Path: macrocystic/microcystic pattern; malignancy suggested by irregular thick wall + septa and solid nodules
DDx: mucinous cystadenoma (no communication with main pancreatic duct); pseudocyst (no intraluminal filling defects)
DDx: serous cystadenoma (no communication with main pancreatic duct)

ERCP:

Cx: seeding to main pancreatic duct resulting in main duct IPMT

Lipoma of Liver

May be associated with: tuberous sclerosis
Size: few mm 13 cm

US:

Prognosis: no malignant potential

Liver Transplant

Indication:

Contraindications: AIDS, extrahepatic malignant tumors, active IVDA/alcohol abuse

Normal posttransplant findings

Vascular Complications in Liver Transplant (9%)

Parenchymal Complications in Liver Transplant

Biliary Complications in Liver Transplant (6-34%)

Time of onset: within first 3 months

Lymphoma of liver

Pattern:

Detection rate (for CT, MRI): <10%

Mesenchymal Hamartoma Of Liver

Histo: disordered arrangement of primitive fluid-filled mesenchyme, bile ducts, hepatic parenchyma; stromal/cystic predominance with cysts of a few mm up to 14 cm in size; no capsule
Age peak: 15 24 months (range from newborn to 19 years); M:F = 2:1
Location: right lobe:left lobe = 6:1; 20% pedunculated
Size: 5 29 (mean 16) cm

US:

CT:

MR:

NUC:

P.730

Angio:

Metastases To Gallbladder

Organ of origin: melanoma, renal cell carcinoma (late in course of disease), lymphoma (in AIDS), malignant fibrous histiocytoma
in children: embryonal cell sarcoma, rhabdomyosarcoma

Metastases To Liver

Incidence: the liver is the most common metastatic site after regional lymph nodes; incidence of metastatic carcinoma is 20 greater than primary carcinoma; metastases represent 22% of all liver tumors in patients with known malignancy
Organ of origin: colon (42%), stomach (23%), pancreas (21%), breast (14%), lung (13%)
in children: neuroblastoma, Wilms tumor
Location: both lobes (77%), right lobe (20%), left lobe (3%)
Number: multiple (50 98%), solitary (2%)
Size: >33% smaller than 2 cm

Enhancement characteristics compared with normal liver:

NUC: 80 95% sensitivity in lesions >1.5 cm;

lesions <1.5 cm are frequently missed; sensitivity increases with metastatic deposit size, peripheral location, and use of SPECT
NECT: important for hypervascular tumors (eg, renal cell carcinoma, carcinoid, islet cell tumors), which may be obscured by CECT

CECT:

Technique:

CT-Angiography (most sensitive imaging modality):

Indication: patients with potentially resectable isolated liver metastases/preoperative to partial hepatectomy for detection of additional metastases (additional lesions detected in 40 55%)

CT-delayed iodine scanning:

Rx: Exclusion criteria for metastasectomy:

(1) advanced stage of primary tumor

(2) >4 metastases

(3) extrahepatic disease

(4) <30% normal liver tissue/function available after resection

Calcified Liver Metastases

Incidence: 2 3%
mnemonic for mucinous adenocarcinoma: COBS

Hypervascular Liver Metastases

mnemonic: CHIMP

Hypovascular Liver Metastases

Hemorrhagic Liver Metastases

mnemonic: CT BeComes MR

Echogenic Liver Metastases

Incidence: 25%

Liver Metastases of Mixed Echogenicity

Incidence: 37.5%

Cystic Liver Metastases

mnemonic: LC GOES

Echopenic Liver Metastases

Incidence: 37.5%

Metastases To Pancreas

Frequency: 3 10% (autopsy)
Organ of origin: renal cell carcinoma (30%), bronchogenic carcinoma (23%), breast carcinoma (12%), soft-tissue sarcoma (8%), colonic carcinoma (6%), melanoma (6%)

CECT:

Concomitant intraabdominal metastases to:

DDx: ductal pancreatic adenocarcinoma (uniformly nonenhancing mass, encasement of vessels)

Milk Of Calcium Bile

Associated with: chronic cholecystitis + gallstone obstruction of cystic duct

US:

Mirizzi Syndrome

Frequently associated with: formation of fistula between gallbladder and common hepatic duct

Cholangiography:

DDx: lymphadenopathy, neoplasm of GB/CHD

Mucinous cystic neoplasm

Frequency: 10% of pancreatic cysts; 1% of pancreatic neoplasms
Mean age: 50 years (range of 20 95 years); in 50% between 40 60 years; M:F = 1:9
Path: large smooth round/lobulated multiloculated cystic mass encapsulated by a layer of fibrous connective tissue
Histo: similar to biliary and ovarian mucinous tumors; cysts lined by tall columnar, mucin-producing cells subtended by a densely cellular mesenchymal stroma (reminiscent of ovarian stroma), often in papillary arrangement, lack of cellular glycogen

(a) mucinous cystadenoma

(b) mucinous cystadenocarcinoma = stratified papillary epithelium

P.732

Intraductal Papillary Mucinous Tumor (IPMT)
Location: often in pancreatic tail (90%)/body, infrequently in head

US:

CT:

Angio:

Metastases:

Prognosis: invariable transformation into cystadenocarcinoma; 17-63% 5-year survival rate
Rx: complete surgical excision (5-year survival rate of 74-90%)

DDx:

Mirizzi Syndrome

Multiple Bile Duct Hamartomas

Incidence: 0.15-2.8% of autopsies
Etiology: failure of involution of embryonic bile ducts
Histo: cluster of proliferated bile ducts lined by single layer of cuboidal cells embedded in fibrocollagenous tissue with single ramified lumen, communication with biliary system usually obliterated
Associated with: fibropolycystic liver disease
Size: 0.1-10 mm

CT:

US:

MR:

P.733

Angio:

DDx:

Multiple Endocrine Neoplasia

Theory: cells of involved principal organs originate from neural crest and produce polypeptide hormones in cytoplasmic granules, which allow amine precursor uptake and d ecarboxylation = APUD cells
    reminder:
Type 1 = Wermer syndrome PPP
Type 2 = Sipple syndrome (type 2A) PMP
Type 3 = Mucosal neuroma syndrome (type 2B) MPM

MEN 1 Syndrome

Cause: genetic defect on chromosome 11

Organ involvement (PPP):

May be associated with:

Screening population: <35-year old patient with HPT, 2 endocrine organ tumors, 1st-degree relative of MEN 1 patient

Imaging surveillance:

Types of Multiple Endocrine Neoplasia
MEA Type 1 Type 2 Type 3
Pituitary adenoma +
Parathyroid adenoma + +
Medullary thyroid carcinoma + +
Pancreatic island cell tumor +
Pheochromocytoma + +
Ganglioneuromatosis +

MEN 2 Syndrome

Cause: genetic defect on chromosome 10

Organ involvement (PMP):

May be associated with: carcinoid tumors, Cushing disease
Screening population: all patients with medullary thyroid cancer/pheochromocytoma, 1st-degree relative of MEN 2 patient

Imaging surveillance:

MEN 3 Syndrome

Cause: new mutation

Organ involvement (MPM):

P.734

Pancreas Divisum

Prevalence: 4 9 14% in autopsy series; 2 8% in ERCP series; 3 7% in normal population; 12 26% in patients with idiopathic recurrent pancreatitis
Hypothesis: relative/actual functional stenosis of minor papilla predisposes to nonalcoholic recurrent pancreatitis in dorsal segment
Age: young/middle-aged adult

Pancreatography:

CT:

Pancreatic Acinar Cell Carcinoma

Age: 40 81 (mean 62) years; M:F = 86:14; 87% Caucasian
Prognosis: median survival of 7 9 months
DDx: (1) pancreatic adenocarcinoma (small, irregular, locally invasive, without capsule, biliary obstruction if located in head of pancreas)

(2) Nonfunctioning islet-cell tumor

(3) Microcystic cystadenoma

(4) Solid and papillary epithelial neoplasm (5) Oncocytic tumor of pancreas

Pancreatic Ductal Adenocarcinoma

Incidence: 95% of malignant tumors of pancreas; 5th leading cause of cancer death in the United States (27,000 per year)
Etiology: alcohol abuse (4%), diabetes (2 more frequent than in general population, particularly in females), hereditary pancreatitis (in 40%); cigarette smoking (risk factor 2 x)
Path: scirrhous infiltrative adenocarcinoma with a dense cellularity + sparse vascularity
Peak age: 7th (range, 4th 8th) decade; M:F = 2:1
Stage I = confined to pancreas

II = + regional lymph node metastases

III = + distant spread

Extension:

Metastases: liver (30 36%), regional lymph nodes >2 cm (15 28%), ascites from peritoneal carcinomatosis (7 10%), lungs (pulmonary nodules/lymphangitic), pleura, bone
Location: pancreatic head (60%); body (15%); tail (5%); diffuse involvement (20%)
Size: 2 10 cm (in 60% between 4 6 cm)

UGI:

BE:

CT (75 96% detection rate for dynamic CT scan):

US:

MR (no diagnostic improvement over CT; valuable in evaluation of an enlarged pancreatic head):

Angiography (70% accuracy):

Cholangiography:

Pancreatography (abnormal in 97%):

Prognosis:

Survival rate & tumor size:

DDx: focal pancreatitis, islet cell carcinoma, metastasis, lymphoma, normal variant

Pancreatic Islet Cell TUmors

Origin: embryonic neuroectoderm, derivatives of APUD (amine precursor uptake and decarboxylation) cell line arising from islet of Langerhans (APUDoma)
Prevalence: 1-5:1,000,000 population/year; isolated or part of MEN I syndrome (= Wermer syndrome)
Path: (a) small tumor: solid well-demarcated

(b) large tumor: cystic changes + necrosis + calcifications
In order of frequency: insulinoma > gastrinoma > glucagonoma > VIPoma > somatostatinoma
Histo: sheets of small round cells + numerous stromal vessels

Average time from onset of symptoms to diagnosis is 2.7 years

Classification:

Metastases: in 60-90% to liver regional lymph nodes

US:

CT (71-82% sensitive)

MR:

NUC (70 90% sensitive, only 50% sensitive for gastrinomas + insulinomas)

Hepatic venous sampling (88% sensitive):

Prognosis: 50% 5-year survival rate
DDx: (1) Pancreatic ductal adenocarcinoma (hypovascular, smaller, encasement of SMA + celiac trunk)

(2) Microcystic adenoma (benign tumor, small cysts, older women)

(3) Metastatic tumor: renal cell carcinoma (clinical Hx)

(4) Solid and papillary epithelial neoplasm (young female, hemorrhagic areas)

(5) Paraganglioma (6) Sarcoma (rare)

ACTH-producing Tumor

Prognosis: almost all malignant with metastases at time of diagnosis

Gastrinoma

Age: 8% in patients <20 years; M > F
Histo: in cells/ cells
Path: (a) islet cell hyperplasia (10%)

(b) benign adenoma (30%): in 50% solitary, in 50% multiple (especially in MEN 1)

(c) malignant (50 60%) with metastases to liver, spleen, lymph nodes, bone
Associated with: MEN 1 (in 50 60%); the most common islet cell tumor in MEN 1

Angio:

CT:

MR:

Sensitivity of preoperative localization:

Rx: surgery curative in 30%
Cx: frequently malignant degeneration (liver metastases at time of diagnosis in 30%)

Glucagonoma

Incidence: uncommon tumor
Age: middle age; M < F
Histo: derived from cells
Associated with: MEN
Cx: deep vein thrombosis + pulmonary embolism
Prognosis: in 60 80% malignant transformation (liver metastases at time of diagnosis in 50 60%); 55% 5-year survival rate

P.737

Insulinoma

Age: 4th 6th decade; M:F = 2:3
Associated with: MEN type I (in 10%)
Path: (a) single benign adenoma (80 90%)

(b) multiple adenomas/microadenomatosis (5 10%)

(c) islet cell hyperplasia (5 10%)

(d) malignant adenoma (5 10%)

US (20 75% preoperative and 75 100% endoscopic + intraoperative sensitivity):

Angio:

CECT (30 75% sensitivity):

MR:

Prognosis: malignant transformation in 5 10%
Rx: surgery curative

Nonfunctioning Islet Cell Tumor

Incidence: 15 25 50% of all islet cell tumors
Histo: derived from either or cells
Age: 24 74 (mean 57) years
Location: predominantly in pancreatic head
Prognosis: in 80 100% malignant transformation with metastases to liver + regional nodes; 60% 3-year survival; 44% 5-year survival
Rx: may respond to systemic chemotherapy

Somatostatinoma

Origin: derived from cells
Incidence: fewer than 200 cases reported in literature
May be associated with: NF 1
Prognosis: 50 90% malignant transformation; metastatic disease to liver/lymph nodes in 50 70% at time of initial diagnosis

VIPoma

Histo: adenoma/hyperplasia; M:F = 1:2

Location:

Prognosis: in 50 80% malignant transformation
DDx: small cell carcinoma of lung/neuroblastoma may also cause WDHH syndrome

Pancreatic Lipomatosis

Predisposing factors:

US:

CT:

Pancreatic Fatty Sparing

Histo: ventral pancreatic anlage has smaller + more densely packed acini with scanty/absent interacinar fat

US:

CT:

Pancreatic Pseudocyst

Etiology: (1) Acute pancreatitis; requires >4 weeks to form; pseudocysts mature in 6 8 weeks

(2) Chronic pancreatitis

(3) Posttraumatic

(4) Pancreatic cancer
Incidence: 2 4% in acute pancreatitis;

10 15% in chronic pancreatitis
Location: 2/3 within pancreas

Atypical location (may dissect along tissue planes in 1/3):

May communicate with: duodenum, stomach, spleen

Plain film/contrast radiograph:

US (pseudocyst detectable in 50-92%; 92-96% accuracy):

CT:

Pancreatography:

Indications for pseudocyst drainage:

Cx (in 40%):

Prognosis: spontaneous resolution (in 20 50%) secondary to rupture into GI tract/pancreatic/bile duct
DDx: pancreatic cystadenoma, cystadenocarcinoma, necrotic pancreatic carcinoma, fluid-filled bowel loop, fluid-filled stomach, duodenal diverticulum, aneurysm

Pancreatic Transplantation

Complications: sepsis, rejection, pancreatitis, pseudocyst, pancreatic abscess (22%), anastomotic leak
Prognosis: 40% survival rate >1 year

Graft-vessel thrombosis in pancreatic transplant (2-19%)

Acute Rejection of Pancreatic Transplant

US:

P.739

Pancreatic Transplantation

Pancreatitis

Cause:

Theories of pathogenesis:

Acute Pancreatitis

Path:

Clinical stages:

Mortality: 100% (40% by 2nd day, 75% by 5th day, 100% by 10th day)

Distribution:

Abdominal film:

CXR (findings in 14 71%):

UGI:

BE:

Cholangiography:

Bone films (findings in 6%):

Cause: metastatic intramedullary lipolysis + fat necrosis + trabecular bone destruction
Time of onset: usually 3 6 weeks after peak of clinical pancreatitis

US (pancreatic visualization in 62 78%):

CT (pancreatic visualization in 98%):

Angiography:

Cx:

Rx:

Mild Acute Pancreatitis (75%)

Path: interstitial edema
Prognosis: improvement within 48 72 hours following conservative therapy with gradual decrease of elevated enzymes
Mortality: 1 5%

Severe Acute Pancreatitis

Associated with: organ failure/local complications
Path: pancreatic cell breakdown + necrosis
Cx: acute fluid collection, pancreatic necrosis, pseudocyst, abscess

Acute Fluid Collections (30 50%)

Path: lack of a defined wall of fibrous/granulation tissue; pancreatic phlegmon [misnomer, no infection] = solid boggy inflammatory mass characterized by edema, infiltration of inflammatory cells + necrosis of retroperitoneal fat
Location: extension into lesser sac, anterior pararenal space, transverse mesocolon, small bowel mesentery, retroperitoneum, pelvis
Prognosis: spontaneous regression (in 40 50%)

Pancreatic Necrosis

Path: clumps of devitalized pancreatic parenchyma + hemorrhage in pancreatic and peripancreatic tissues
Histo: extensive interstitial fat necrosis with vessel damage + necrosis of acinar cells, islet cells, ductal system
Associated with: peripancreatic fat necrosis

Acute Pseudocyst

Path: absence of epithelium-lined wall
Cause: acute pancreatitis, pancreatic trauma, chronic pancreatitis
Time of onset: >4 weeks after acute pancreatitis
Prognosis: persistent pseudocyst usually communicates with pancreatic duct; spontaneous resolution in 44%; <4 cm: resolution anticipated; >7 cm: treatment recommended
Cx: hemorrhage, infection; spontaneous rupture into hollow viscera

PANCREATIC ABSCESS

Time of onset: 2-4 weeks after severe acute pancreatitis
Organism: most commonly due to E. coli
DDx: infected necrosis

Chronic Pancreatitis

Incidence: 4:100,000 (in Western countries)

Etiology:

Plain film:

UGI:

Cholangiopancreatography (most sensitive imaging modality):

US/CT:

MR:

Angiography:

Cx: pancreatic carcinoma (2 4%), jaundice, pseudocyst formation, pancreatic ascites, thrombosis of splenic/mesenteric/portal vein
Rx: surgery for infected pseudocyst, GI bleeding from portal hypertension, common bile duct obstruction, gastrointestinal obstruction
DDx: pancreatic carcinoma (extrapancreatic spread)

Chronic Alcoholic Pancreatitis

Chronic Obstructive Pancreatitis

Etiology:

Nonalcoholic Duct-Destructive Chronic Pancreatitis

Location: body + tail of pancreas

MR:

Pancreatoblastoma

Age: <7 years

Papillary Adenoma Of Bile Ducts

Path: usually solitary tumor/papillomatosis with papillary fronds extending into lumen

P.743

Histo: columnar epithelium supported by connective tissue from lamina propria
Location: common bile duct > right/left hepatic duct
Prognosis: high rate of recurrence after surgical resection
Cx: malignant transformation (rare)

Passive Hepatic Congestion

Cause: CHF, constrictive pericarditis
Pathophysiology: chronic central venous hypertension transmitted to hepatic sinusoids results in centrilobular congestion + eventually hepatic atrophy, necrosis, fibrosis

CT:

DDx: Budd-Chiari syndrome (regional/lobular distribution of reticulated mosaic pattern, caudate lobe hypertrophy)

Peliosis

[pelios, Greek = purple]

Cause: (a)? acquired: chronic infection (disseminated TB), hepatotoxic drugs (androgen-anabolic steroids, corticosteroids, tamoxifen citrate, chemotherapeutic agents, azathioprine, oral contraceptives, thorium dioxide injection), diabetes mellitus, chronic renal failure, advanced malignancy (Hodgkin disease, myeloma, disseminated cancer)

(b) bacillary peliosis hepatis in AIDS (lesions contain bacilli of Rochalimaea species) responsive to antibiotics

(c)? congenital: angiomatous malformation
Histo: (1) Phlebectatic peliosis hepatis (early stage)

= endothelial-lined cysts (=? dilatation of central veins) communicating with dilated hepatic sinusoids + compression of surrounding liver

(2) Parenchymal peliosis hepatis (late stage)

= irregularly shaped cysts without lining communicating with dilated hepatic sinusoids + areas of liver cell necrosis
Associated with: hormonally induced benign/malignant tumors
Location: liver (most common), spleen, bone marrow, lymph nodes, lungs)
Age: fetal life (rare) to adult life

US:

CECT:

MR:

Angio:

Prognosis: reversible after drug withdrawal/progression to hepatic failure/intraperitoneal hemorrhage leading to death

Porcelain Gallbladder

Incidence: 0.6 0.8% of cholecystectomy patients; M:F = 1:5
Histo: (a) flakes of dystrophic calcium within chronically inflamed + fibrotic muscular wall

(b) microliths scattered diffusely throughout mucosa, submucosa, glandular spaces, Rokitansky-Aschoff sinuses
Associated with: gallstones in 90%
Cx: 10 20% develop carcinoma of gallbladder

Portal Hypertension

Classification:

Pathophysiology:

Flow direction:

Spontaneous Portosystemic Shunts
Type of Varices Frequency (%)
Coronary venous 80 86
Esophageal 45 65
Paraumbilical 10 43
Abdominal wall 30
Perisplenic 30
Retrogastric/gastric 2 27
Paraesophageal 22
Omental 20
Retroperitoneal paravertebral 18
Mesenteric 10
Splenorenal 10
Gastrorenal 7
Cx: Acute gastrointestinal bleeding (mortality of 30 50% during 1st bleeding)

Segmental Portal Hypertension

Portosystemic Surgical Connections

Doppler criteria for shunt patency:

Transjugular Intrahepatic Portosystemic Shunt (TIPS)

Indication: patients with esophageal + gastric variceal hemorrhage/refractory ascites due to advanced liver disease with portal hypertension, hepatorenal syndrome
Type of stent: 10-mm Wall stent (curved), Palmaz stent (straight), Strecker stent, spiral Z stent
Shunt surveillance: at regular 3 6-month intervals for

Assessment:

Cx:
  1. Obstruction to flow
    1. Shunt obstruction (38%)

    2. Hepatic vein stenosis

  2. Trauma
    1. Vascular injury
      1. Hepatic artery pseudoaneurysm

      2. Arterioportal fistula

      3. Intrahepatic/subcapsular hematoma

      4. Hemoperitoneum (due to penetration of liver capsule)

    2. Biliary injury
      1. Transient bile duct dilatation (due to hemobilia)

      2. Bile collection

  3. Stent dislodgment with embolization to right atrium, pulmonary artery, internal jugular vein
Mortality: <2% (intraperitoneal hemorrhage)

P.746

TIPS failure

Cause: acute thrombosis, improper stent placement, intimal hyperplasia, hepatic vein stenosis, change in stent configuration, bulging of liver parenchyma into shunt
Prevalence: 31% at 1 year, 42% at 2 years
Pre- and Post-TIPS Baseline Study

(under stable fasting conditions)
  Pre-TIPS Post-TIPS
Portal vein velocity (cm/s) 10 30 40 60
Mean portal vein velocity (cm/s) 18 6 55 7
Portal pressure (mm hg) 37 8 22 6
Shunt peak velocity (cm/s) 0 95 58

Portal Vein Thrombosis

Etiology:

Age: predominantly children, young persons

Acute Portal Vein Thrombosis

Plain film:

UGI:

US:

Doppler-US:

NECT:

CECT:

MR:

P.747

Angio:

Cx: (1) Cavernous transformation (19%)

(2) Hepatic infarction

(3) Bowel infarction

Chronic Portal Vein Thrombosis

Pathophysiology:

CECT:

US:

MR:

Postcholecystectomy Syndrome

Incidence:

Cause:

Richter Syndrome

Etiology: transformation/dedifferentiation of CLL lymphocytes
Incidence in CLL patients: 3 10%
Median age: 59 years
Medium time interval after diagnosis of CLL: 24 months
Location: bone marrow, lymph nodes, liver, spleen, bowel, lung, pleura, kidney, dura
Prognosis: median survival time: 4 months from diagnosis of lymphoma; 14% rate of remission rate

Schistosomiasis

Types:

Cycle:

Infection: cercariae penetrate human skin/buccal mucosa from contaminated water (slow-moving streams, irrigation canals, paddy fields, lakes)
Histo: granulomatous reaction + fibrosis along portal vein branches
Cx: ileus

P.748

Schwachman-Diamond Syndrome

DDx: cystic fibrosis (pancreatic calcifications, cyst formation, abnormal sweat test)

Serous Cystadenoma Of Pancreas

Incidence: approximately 50% of all cystic pancreatic neoplasms
Histo: cyst walls lined by cuboidal/flat glycogen-rich epithelial cells derived from centroacinar cells of pancreas (DDx: lymphangioma), thin fibrous pseudocapsule
Age: 34 88 years; mean age 65 years; 82% over 60 years of age; M:F = 1:2 4
Associated with: von Hippel-Lindau syndrome
Location: any part of pancreas affected, slight predominance for head + neck
Prognosis: no malignant potential
Rx: surgical excision/follow-up examinations
DDx: malignant mucinous cystic neoplasm (younger age, body + tail of pancreas, >10 cm large at presentation)

Solid And Papillary Neoplasm Of Pancreas

Prevalence: 0.17 2.7% of all nonendocrine pancreatic tumors
Mean age: 25 (range 10 74) years; M:F = 1:9; especially in black and East Asian patients
Path: large well-encapsulated mass with considerable hemorrhagic necrosis + cystic degeneration
Histo: sheets + cords of cells arranged around a fibrovascular stroma
Location: tail of pancreas (most frequently)
Prognosis: (1) excellent after excision

(2) metastases (in 4%): omentum, lymph nodes, liver
DDx: (1) Microcystic adenoma (innumerable tiny cysts, older age group)

(2) Mucinous cystic neoplasm (large uni-/multilocular cysts, older age group)

(3) Nonfunctioning islet cell tumor (hypervascular)

(4) Pleomorphic carcinoma of pancreas (smaller tumor in older patient)

(5) Pancreatoblastoma (childhood tumor)

(6) Calcified hemorrhagic pseudocyst

Splenic Angiosarcoma

Incidence: rare, <100 cases in literature
Cause: usually not due to thorotrast or toxic exposure to vinyl chloride/arsenic as in liver angiosarcoma
Age: 50 60 years

MR:

Prognosis: 20% survival rate after 6 months

Splenic Hamartoma

Etiology: congenital
May be associated with: hamartomas elsewhere as in tuberous sclerosis
Histo:
  1. mixture of white + red pulp (most common)

  2. white pulp subtype = aberrant lymphoid tissue

  3. red pulp subtype = aberrant complex of sinusoids

Splenic Hemangioma

Cause: congenital, arising from sinusoidal epithelium
Prevalence: 0.03 14% (autopsy); M > F

Most common primary splenic tumor!
Age: 20 50 years
Histo: proliferation of vascular channels lined by single layer of endothelium; mostly of cavernous type; may contain areas of infarction, hemorrhage, thrombosis, fibrosis
Associated with: generalized angiomatosis Klippel-Tr naunay-Weber syndrome, Beckwith-Wiedemann syndrome, Turner syndrome
Prognosis: slow growth, thus becoming symptomatic in adulthood
Cx: (1) Spontaneous splenic rupture (in up to 25%)

(2) Kasabach-Merritt syndrome (= anemia, thrombocytopenia, coagulopathy) with large hemangioma

(3) Portal hypertension

(4) Malignant degeneration

Splenic Infarction

mnemonic: PSALMS
Anatomy: branches of the splenic artery are noncommunicating end arteries
Cx: acute febrile illness, abscess formation, pseudocyst formation, splenic rupture, hemorrhage

Splenosis

= posttraumatic autotransplantation of splenic tissue to other sites (heterotopic splenic tissue)

Age: young men with history of trauma/splenectomy
Time of detection: mean of 10 years (range of 6 months to 32 years) after trauma
Location: diaphragmatic surface, liver, greater omentum, small bowel serosa, parietal peritoneum, pleura after diaphragmatic rupture (attaches to peritoneal/pleural surface)
Size: few mm to 3 cm (due to limited blood supply from local neovascularization)
DDx: accessory spleen

Spontaneous Perforation Of Common Bile Duct

Pathogenesis: unknown (? CBD obstruction, localized mural malformation, ischemia, trauma)
Age: 5 weeks to 3 years of age

Thorotrastosis

Distribution: phagocytized by RES + deposited in liver (70%), spleen (30%), bone marrow, abdominal lymph nodes (20%)
Cx: hepatic fibrosis, angiosarcoma (50%), cholangiocarcinoma, hepatocellular carcinoma (latency period of 3 40 years; mean 26 years)

Tyrosinemia

= rare autosomal recessive metabolic disorder

Country: increased prevalence in Canadian province of Quebec and parts of Scandinavia
Biochemistry: deficiency of enzyme fumarylacetoacetase (last step in catabolic pathway of tyrosine, serum methionine, urinary succinylacetone); elevated levels of serum tyrosine as a precursor of dopamine, norepinephrine, epinephrine, melanin, thyroxin
Prenatal Dx: enzyme deficiency demonstrable in hepatocytes, skin fibroblasts, lymphocytes, amniocytes
Cx: hepatocellular carcinoma (in 37% beyond 2 years of age)
Rx: (1) Diet restricted in phenylalanine + tyrosine (alleviates kidney damage but does not prevent fatal outcome)

(2) 2-2-nitro-4-trifluoro-methylbenzoyl-1,3-cyclohexanedione (NTBC) inhibits 4-hydroxyphenylpyruvate dioxygenase + prevents formation of maleylacetoacetate and fumarylacetoacetate

(3) Liver transplantation (before HCC develops)

P.751

Undifferentiated Sarcoma Of Liver

Incidence: 4th/5th most common liver tumor in pediatric population
Age: <2 months (in 5%); 6 10 years (in 52%); by 15 years (in 90%); up to 49 years; M:F = 1:1
Histo: primitive undifferentiated stellate/spindle-shaped sarcomatous cells closely packed in whorls + sheets/scattered loosely in a myxoid ground substance with foci of hematopoiesis (50%)
Location: right lobe (75%); left lobe (10%);both lobes (15%)
Prognosis: mostly results in death within 12 months
DDx: mesenchymal hamartoma

(a) solid lesion + cystic degeneration:

hepatocellular carcinoma, fibrolamellar carcinoma, intrahepatic cholangiocarcinoma, angiosarcoma, epithelioid hemangio-endothelioma, other sarcomas, lymphoma, metastatic disease, hepatocellular adenoma

(b) solitary cystic lesion:

biliary cystadenoma/biliary carcinoma, cystic degeneration of hepatocellular carcinoma, bacterial/parasitic abscess, metastatic disease, posttraumatic resolving hematoma

Wandering Spleen

Cause: embryologically absent/malformed gastrosplenic + splenorenal ligaments; deficient/lax abdominal musculature (prune-belly syndrome, pregnancy)
Age: any (higher frequency in women of childbearing age)
Rx: 1. Splenectomy (4% postsplenectomy sepsis)

2. Splenopexy

3. Conservative treatment (if asymptomatic)

Related

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