pancreas divisum + bile duct carcinoma (in adult)

Location:   2^nd portion of duodenum (85%);
1^st / 3^rd portion of duodenum (15%)

•  mostly asymptomatic with incidental discovery

•  neonate  :  persistent vomiting ← “gastric outlet” obstruction (in 10%)

•  adult  :  nausea, vomiting (60%), abdominal pain (70%), jaundice (50%), hematemesis (10%); symptoms of peptic ulcer disease (25%) / acute pancreatitis (13%)

√  “double bubble” = dilated duodenal bulb (= smaller distal bubble) + distended stomach (= larger proximal bubble)

√  proximal duodenal dilatation

OB–US:   √polyhydramnios

UGI:

√  eccentric narrowing with lateral notching + medial retraction of 2^nd part of duodenum

√  concentric ringlike narrowing of mid-descending duodenum between major and minor papilla

√  reverse peristalsis, pyloric incompetency

CT:

√  enlargement of pancreatic head

√  pancreatic tissue encircling descending duodenum

ERCP (most specific) / MR pancreatography (MRCP):

√  normally located main duct in pancreatic body + tail

√  small aberrant duct encircles duodenum (= originates anterior to + passes posterior to duodenum) communicating with:

›  main duct of Wirsüng (in 85%)

›  accessory duct of Santorini

›  intrapancreatic common bile duct

Cx:   in adults increased incidence of

(1)  Periampullary peptic ulcers

(2)  Pancreatitis (15–20%): usually confined to pancreatic head and annulus

(3)  Duodenal obstruction (10%)

Rx:   gastrojejunostomy / duodenojejunostomy

AGENESIS OF DORSAL PANCREAS

Variation:   complete (extremely rare) / partial

May be associated with:  heterotaxia (abnormal situs, polysplenia), intestinal malrotation

•  nonspecific abdominal pain ← ? pancreatitis

•  diabetes (in many)

√  short round pancreatic head adjacent to duodenum

√  absence of pancreatic neck, body, tail, duct of Santorini, minor duodenal papilla

DDx:   pancreatic carcinoma with upstream pancreatic atrophy

ASCARIASIS

Organism:   nematode (roundworm) Ascaris lumbricoides, 15–50 cm long + 3–6 mm thick adult worm; life span of 1 year

◊  3^rd most common helminthic infection (after hookworm + trichuriasis)

Endemic:   in tropical + subtropical areas

(a)  in parts of Africa (along Gulf Coast, Nigeria), Southeast Asia, China, South America: 90%

(b)  in USA: 12% in blacks, 1% in whites; endemic in Appalachian range + Ozark Mountains

Prevalence:   most common cosmopolitan parasitic infection (25% of world population infected); 1 billion humans harbor the roundworm [ cosmos , Greek = world; polites , Greek = citizen]

Infection:   fecal-oral route

Cycle:

contaminated water / soil / vegetable → ingestion of eggs; eggs hatch (= release larvae) in duodenum → larvae penetrate intestinal wall + migrate into mesenteric lymphatics and venules;→ carried to lungs via right heart + pulmonary artery; → mature in pulmonary capillary bed to 2–3 mm length → burrow into alveoli → ascend in bronchial tree; through swallowing again reach small intestine → mature in jejunum into adult worms within 2.5 months (worms may migrate and settle in biliary + pancreatic ducts) → production of 200,000 eggs daily leave body by fecal route

Age:   children 1–10 years of age

•  pulmonary + intestinal symptoms:

•  fever, cough, expectoration (hematemesis / pneumonitis)

•  appendicitis

•  biliary symptoms:

•  jaundice (if bile ducts infested); abnormal liver function tests

•  biliary colic ← Ascaris secretions induce spasm of sphincter of Oddi

•  eosinophilia:

•  hypereosinophilia only present during acute stage of larval migration; Löffler syndrome = pulmonary eosinophilia

Location:   jejunum > ileum (99%), duodenum, stomach, CBD, pancreatic duct

Barium study:

√  15–35 cm long elongated tubular filling defects

√  whirled appearance, occasionally in coiled clusters (“bolus of worms”)

√  ± barium-opacification of enteric canal within nematode

CT:

√  worms are hyperattenuating relative to bile

MR:

√  worms exhibit low signal intensity on T2WI

√  fluid-filled GI tract of worms hyperintense on T2WI

CXR:

√  migratory patchy alveolar infiltrates that characteristically clear within 10 days

√  lobar consolidation + alveolar hemorrhage

Dx:   fecal examination (eggs in stool), larvae in sputum

Rx:   mebendazole

Ascaris-induced Pancreatitis

=  occasional migration of worm through ampulla of Vater into pancreaticobiliary tree via abnormally open ampullary orifice ← preexisting biliary tract disease / endoscopic sphincterotomy

◊  Most common parasitic cause of pancreatitis!

Mean age:  35–42 years; M÷F = 1÷3

US:

√  biliary / pancreatic ductal dilatation

√  pancreatic + peripancreatic inflammation

√  echogenic tubular structure without acoustic shadowing within bile / pancreatic duct with 2–4-mm wide central sonolucent line (= worm’s digestive tract)

√  worm may slowly move at real-time imaging

Cx:     biliary colic, cholangitis, acute cholecystitis, hepatic abscess, acute pancreatitis, septicemia

AUTOSOMAL DOMINANT POLYCYSTIC DISEASE

=  POLYCYSTIC LIVER DISEASE

=  part of spectrum of fibropolycystic liver disease

Etiology:   biliary ductal plate malformation at the level of the small intrahepatic bile ducts with progressive dilation of the abnormal noncommunicating bile ducts of biliary hamartomas

M÷F = 1÷2

Associated with:   polycystic kidney disease (in 50%)

•  upper abdominal pain + distension from hepatomegaly

√  enlarged diffusely cystic liver: cysts of 1 mm – 12 cm in diameter

√  calcifications of cyst wall ← hemorrhage / infection

√  ± diffuse dilatation of intra- and extrahepatic bile ducts

Cx:   infection, compression, bleeding, rupture of cysts

BANTI SYNDROME

=  NONCIRRHOTIC IDIOPATHIC PORTAL HYPERTENSION = NONCIRRHOTIC PORTAL FIBROSIS = HEPATOPORTAL SCLEROSIS

=  syndrome characterized by

(1)  Splenomegaly

(2)  Hypersplenism

(3)  Portal hypertension

Etiology:   increased portal vascular resistance possibly ← 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; common in India + Japan

•  elevated portal vein pressure (without cirrhosis, parasites, venous occlusion)

•  normal liver function tests, cytopenia (← hypersplenism)

•  normal / slightly elevated hepatic venous wedge pressure

√  esophageal varices

√  patent hepatic veins

√  patent extrahepatic portal vein + multiple collaterals

Prognosis:   90% 5-year survival; 55% 30-year survival

BILE LEAK

Cause:

1.   Post orthotopic liver transplantation

2.   Pancreaticoduodenectomy

3.   Hepatic or biliary surgery

4.   Cholecystectomy (2%): laparoscopic > open

5.   Radiofrequency ablation, percutaneous biliary drainage

6.   Transcatheter arterial chemoembolization

Prevalence:   7% after laparoscopic cholecystectomy

Time of onset:   during 1^st postoperative week

•  asymptomatic subclinical bile leak (7%)

•  abdominal pain, fever, nausea, vomiting

Location:   cystic duct stump / ducts of Luschka (= subvesical / accessory biliary ducts)

Cholescintigraphy:

√  DIAGNOSTIC but with poor anatomic definition and spatial resolution necessitating a secondary diagnostic evaluation (especially ERCP)

MRCP with hepatobiliary contrast medium:

Agents:   gadoxetate disodium (Eovist^®) with 50% liver excretion 20 minutes after administration; gadobenate dimeglumine (MultiHance^®) with 5% liver excretion 60–120 minutes after administration

√  dynamic biliary imaging during hepatobiliary phase with improved characterization of biliary anatomy

ERCP:

√  depicts peripheral sites of leakage that may not be filled with retrograde injection

Prognosis:   high morbidity + mortality rates if undiagnosed

Rx:   endoscopic / surgical management

BILIARY CYSTADENOCARCINOMA

=  BILE DUCT CYSTADENOCARCINOMA

=  rare malignant multilocular cystic tumor originating from biliary cystadenoma

•  hemorrhagic internal fluid

√  nodularity with septations are suggestive of malignancy

√  coarse calcifications

DDx:   NO image differentiation from biliary cystadenoma

BILIARY CYSTADENOMA

=  BILE DUCT CYSTADENOMA

=  very rare benign multilocular cystic tumor originating in bile ducts as premalignant form of biliary cystadenocarcinoma; probably deriving from ectopic nests of primitive biliary tissue

Frequency:   4.6% of all intrahepatic cysts of bile duct origin

Age:   > 30 years (82%), peak incidence in 5^th decade; M÷F = 1÷4; predominantly in Caucasians

Path:   multilocular cystic tumor containing proteinaceous fluid with well-defined thick capsule

Histo:   single layer of cuboidal / tall columnar mucin-secreting 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)

•  chronic abdominal pain

•  dyspepsia, anorexia, nausea + vomiting, jaundice

•  abdominal swelling with palpable mass (90%)

Size:   1.5–35 cm (reportedly up to 11 liters of liquid content)

√  well-defined cystic mass containing clear / cloudy, serous / mucinous / gelatinous, purulent / hemorrhagic / bilious fluid with hemosiderin / cholesterol / necrosis

√  thick fibrous capsule

√  papillary excrescences + mural nodules

√  septations between cysts

US:

√  ovoid multiloculated anechoic mass with highly echogenic septations / papillary growths

√  may contain fluid-fluid levels

CT:

√  multiloculated mass of near water density

√  contrast enhancement in wall + internal septa

MR:

√  locules with variable SI on T1WI + T2WI depending on their protein content

Angio:

√  avascular mass with small clusters of peripheral abnormal vessels

√  stretching + displacement of vessels

√  thin subtle blush of neovascularity in septa + wall

Rx:   surgical resection (recurrence common)

DDx:   biliary cystadenocarcinoma, 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

Frequency:   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:

duodenum (70%), colon (26%), stomach (4%), jejunum, ileum, hepatic artery, portal vein (caused death of Ignatius de Loyola), bronchial tree, pericardium, renal pelvis, ureter, urinary bladder, vagina, ovary

A.  CHOLECYSTODUODENAL FISTULA (51–80%)

1.   Perforated gallstone (90%):

associated with gallstone ileus in 20%

2.   Perforated duodenal ulcer (10%)

3.   Surgical anastomosis

4.   Gallbladder carcinoma

B.  CHOLECYSTOCOLIC FISTULA (13–21%)

C.  CHOLEDOCHODUODENAL FISTULA (13–19%)

due to perforated duodenal ulcer disease

D.  MULTIPLE FISTULAE (7%)

√  pneumobilia = branching tubular radiolucencies, more prominent centrally within the liver

√  barium filling of biliary tree

√  shrunken gallbladder mimicking pseudodiverticulum of duodenal bulb

√  multiple hyperechoic foci with dirty shadowing

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

BUDD-CHIARI SYNDROME

=  syndrome of global / segmental hepatic venous outflow obstruction at level of hepatic veins / IVC

Cause:

A.  IDIOPATHIC (66%)

B.  THROMBOSIS

(a)  myeloproliferative disorder:

polycythemia rubra vera (⅓), essential thrombocytosis

(b)  hypercoagulable state:

mnemonic:   6 P’s

Paroxysmal nocturnal hemoglobulinuria (12%)

Platelets (thrombocytosis)

Pill (birth control pills)

Pregnancy + Postpartum state

Polycythemia rubra vera

Protein C deficiency

also: sickle cell disease

(c)  injury to vessel wall:

phlebitis, trauma, hepatic radiation injury, chemotherapeutic + immunosuppressive drugs in patient with bone marrow transplant, venoocclusive disease from pyrrolizidine alkaloids (Senecio) found in medicinal bush teas in Jamaica

C.  NONTHROMBOTIC OBSTRUCTION

(a)  compression or invasion of IVC / hepatic veins:

›  benign: cirrhosis, hematoma, abscess

›  malignant: renal cell carcinoma, adrenal carcinoma, hepatoma, cholangiocarcinoma, metastasis, primary leiomyosarcoma of IVC, Hodgkin disease

(b)  membranous obstruction of suprahepatic IVC

=  IVC diaphragm (believed to be a congenital web / acquired lesion from long-standing IVC thrombosis); common in Oriental + Indian population (South Africa, India, Japan, Korea, Israel); very rare in Western countries

(c)  right atrial tumor: atrial myxoma

(d)  constrictive pericarditis

(e)  right heart failure

D.  SYSTEMIC INFLAMMATION / INFECTION

1.   Inflammatory bowel disease

2.   Behçet syndrome

Pathophysiology:

hepatic venous thrombosis → elevation of sinusoidal pressure → diminished / reversed portal venous flow → centrilobular congestion → necrosis + atrophy

(a)  acute form (= no time for development of collateral veins) → rapid development of hepatic necrosis

(b)  subacute / chronic form (venous thrombosis incomplete) → peripheral atrophy + preservation of central region with caudate lobe hypertrophy (drained by accessory veins)

In 25% associated with:  portal vein thrombosis

Age:   all ages; M < F

•  right upper quadrant pain, lower-extremity edema

•  shortness of breath ← decreased cardiac return

•  nonspecific elevated transaminases, jaundice

Location:

√  gallbladder wall thickening > 6 mm

√  portal vein diameter > 12 mm (in adults), > 8 mm (in children)

MR:

√  reduction in caliber / complete absence of hepatic veins

√  “comma” sign = multiple comma-shaped intrahepatic flow voids ← intrahepatic collaterals

√  hyperintense thrombi

Doppler US (85–100% sensitive, 85% specific):

√  one / more major hepatic veins reduced in size to < 3 mm / filled with thrombus / not visualized

√  stenoses of hepatic veins

√  communicating intrahepatic venous collaterals

√  decreased / absent / reversed blood flow in hepatic veins

√  flat flow / loss of cardiac modulation in hepatic veins

√  demodulated portal venous flow = disappearance of portal vein velocity variations with breathing

√  slow flow of < 11 cm/sec / hepatofugal flow in portal vein

√  portal vein congestion index > 0.1 [cm • sec] (= ratio between cross-sectional area [cm²] and blood flow velocity [cm/sec])

√  portal vein thrombosis (20%)

√  compression of IVC by enlarged liver / caudate lobe

√  sluggish / reversed / absent blood flow within IVC

√  hepatic artery resistive index > 0.75

NUC (^99mTc-sulfur colloid):

√  central region of normal activity (= hot caudate lobe ← venous drainage of hypertrophied caudate lobe into IVC by separate vein) surrounded by greatly diminished activity

√  colloid shift to spleen + bone marrow

√  wedge-shaped focal peripheral defects

Angio (inferior venocavography, hepatic venography):

√  absence of main hepatic veins

√  spider web pattern of collateral + recanalized veins

√  high-pressure gradient between infra- and suprahepatic portion of IVC ← enlarged liver

√  stretching + draping of intrahepatic arteries with hepatomegaly

√  inhomogeneous prolonged intense hepatogram with fine mottling

√  large lakes of sinusoidal contrast accumulation

Portography:

√  central hepatic enhancement (normal hepatopetal flow)

√  reversed portal flow in liver periphery (supplied only by hepatic artery)

√  bidirectional / hepatofugal main portal vein flow

Dx:      liver biopsy

Rx:      control of ascites with diuretics + sodium restriction; anticoagulation, thrombolytic therapy, surgery / balloon dilatation (depending on etiology); transjugular portosystemic shunt (in preparation for) orthotopic liver transplantation (for advanced cases)

Acute Budd-Chiari Syndrome (⅓)

◊  Caudate lobe has not had time to hypertrophy!

•  TRIAD:

•  rapid onset of abdominal pain (liver congestion)

•  insidious onset of intractable ascites

•  hepatomegaly without derangement of liver function

•  jaundice

√  enlarged morphologically normal liver

√  splenomegaly

√  ascites (97%)

NECT:

√  diffusely hypoattenuating liver

√  IVC + hepatic veins:

√  narrowed lumina (without thrombus)

√  hyperattenuating lumina containing thrombus (in 18–53%)

√  enlarged inferior right hepatic vein (18%)

CECT:

√  normal early enhancement of caudate lobe and central portion around IVC + decreased enhancement of peripheral liver (← portal and sinusoidal stasis) during arterial phase

√  “flip-flop” pattern during portal venous phase:

√  decreased attenuation (washout) of enhancing central areas

√  increasing patchy inhomogeneous enhancement in liver periphery ← contrast inflow from capsular veins

MR:

√  peripheral liver parenchyma of moderately low SI on T1WI + moderately high SI on T2WI compared with central portion

√  diminished + mottled peripheral enhancement

Subacute Budd-Chiari Syndrome

•  portal hypertension, varying degrees of liver decompensation

√  diffuse peripheral hypoattenuation ← hepatocellular necrosis + steatosis

Chronic Budd-Chiari Syndrome (²/_³)

•  insidious onset of jaundice, intractable ascites

•  portal hypertension, variceal bleeding

•  renal impairment (in 50%)

√  dysmorphic liver:

√  nonsegmental / lobar atrophy of affected liver (← extensive fibrosis) with diminished attenuation before + after contrast administration

√  compensatory hypertrophy of caudate lobe (88%) + central parenchymal segments of right lobe + medial segment of left lobe:

√  width of caudate ÷ right lobe ≥ 0.55 (DDx: cirrhosis)

√  visualization of collateral pathways

(a)  portosystemic: paraumbilical vein

(b)  bypassing IVC: azygos, hemiazygos

(c)  intrahepatic collateral veins (almost DIAGNOSTIC): right / middle hepatic vein → inferior right hepatic vein; hepatic vein → portal vein

√  development of 1–4 cm regenerative nodules (in areas of adequate blood supply)

√  ascites

CECT:

√  invisible IVC ± hepatic veins ← collapse / diminished flow rate:

√  nonvisualization of hepatic veins (75%) / vein diameter < 3 mm (measured 2 cm from IVC)

√  ± narrowing / obstruction of intrahepatic IVC

√  progressive heterogeneous patchy enhancement radiating outward from major portal vessels

√  “reticulated mosaic” enhancement = diffuse patchy lobular enhancement separated by irregular linear areas of low density in central area

√  delayed homogeneous enhancement of entire liver after several minutes

√  reversed portal venous blood flow ← increased postsinusoidal pressure produced by hepatic venous obstruction / rarely infarcts

Color Doppler:

√  PATHOGNOMONIC “bicolored” hepatic veins ← intrahepatic collateral pathways

MR:

√  absence of flow within hepatic veins

√  minimal differences in SI between central and peripheral portions of liver

√  intrahepatic collateral vessels

CANDIDIASIS OF LIVER

=  almost exclusively seen in immunocompromised patients (acute leukemia, chronic granulomatous disease of childhood, renal transplant, chemotherapy for myeloproliferative disorders)

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

◊  Most common systemic fungal infection in immunocompromised patients!

•  abdominal pain, elevated alkaline phosphatase

•  persistent fever in neutropenic patient whose leukocyte count is returning to normal

√  hepatomegaly

√  “target” / “bull’s-eye” sign = multiple small hypoechoic / hypoattenuating masses with centers of increased echogenicity / attenuation distributed throughout liver

◊  Bull’s-eye lesion becomes visible only when neutropenia resolves!

√  hyperintense lesions on T2WI

NUC:

√  uniform uptake / focal photopenic areas

√  diminished ⁶⁷Ga uptake

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

[Jacques Caroli (1902–1979), surgeon in Paris, France]

=  COMMUNICATING CAVERNOUS ECTASIA OF INTRAHEPATIC BILE DUCTS

◊  Original classification as Type V choledochal cyst (Todani classification) is NO longer accepted!

=  rare congenital autosomal recessive disorder characterized by multifocal segmental saccular cystic dilatation of large intrahepatic bile ducts

Path:   communication with biliary tree

Age:   childhood + 2^nd–3^rd 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, cholangiocarcinoma

•  recurrent cramplike right upper quadrant pain

•  bouts of fever ← cholangitis ← bile stasis

•  transient jaundice ← bile stasis ← blocking stone / sludge

•  cirrhosis / portal hypertension (very rare)

Location:   diffuse / segmental or lobar

Types:

(1)  pure form (type 1): attacks of cholangitis + intraductal stone formation

(2)  complex form (type 2) – more common: associated with hepatic fibrosis / other ductal plate malformations

√  multiple small localized / diffusely scattered cysts converging toward porta hepatis communicating with bile ducts

√  beaded ducts with alternating dilated and strictured segments

√  sludge / pus / calculi in dilated ducts

CT / US/ MR:

√  “central dot” sign = enhancing fibrovascular bundle of portal vein radicles completely surrounded by cystically altered dilated intrahepatic bile ducts (IBD)

Cholangiography and MRCP (DIAGNOSTIC):

√  segmental saccular > fusiform beaded dilatation of intrahepatic bile ducts extending to periphery of liver up to 5 cm in diameter

√  ± filling defects ← intraductal calculi

√  bridge formation across dilated lumina

√  intraluminal bulbar protrusions

√  frequent ectasia of extrahepatic ducts + CBD

Dx:   ERCP, direct cholangiography, MRCP

Caroli Syndrome

=  both features of Caroli disease and congenital hepatic fibrosis

=  arrest of bile duct remodeling during embryogenesis + during later development of more peripheral biliary ramifications

•  hematemesis ← ruptured esophageal varices ← portal hypertension

CHOLANGIOCARCINOMA

=  primary malignancy arising from cholangiocyte of biliary tract

Frequency:   0.5–1.0% of all cancers;

10% of hepatic primary malignancies

◊  2^nd most common primary hepatobiliary cancer after HCC!

Anatomic classification:

A.  INTRAHEPATIC (PERIPHERAL)

peripheral / distal to 2^nd-order branches 8–13%

B.  PERIHILAR (CENTRAL) = Klatskin tumor
at bifurcation / 1^st-order branches

confluence of hepatic ducts   10–26%

C.  EXTRAHEPATIC

common hepatic duct   14–37%

proximal CBD   15–30%

distal CBD   30–50%

cystic duct   6%

D.  GALLBLADDER

Path (Japanese Liver Cancer Study Group):

(a)  mass-forming (= nodular / exophytic) type:

commonly in peripheral cholangiocarcinoma

•  homogeneous sclerotic mass typically without hemorrhage / necrosis

•  central portion with variable degree of fibrosis + coagulative necrosis with scanty tumor cells

(b)   periductal infiltrating / diffuse type:

commonly in hilar + extrahepatic cholangiocarcinoma

•  elongated spiculated / branching growth along dilated / narrowed bile duct

(c)  intraductal tubular polypoid / papillary type:

•  infrequent slow growing tumor with relatively favorable prognosis

•  frequently associated with marked mucin production

(d)  mixed = combination of mass-forming + periductal

Histo:   well / moderately / poorly differentiated ductal adenocarcinoma (most common) / papillary / mucinous / signet-ring cell / mucoepidermoid / adenosquamous adenocarcinoma with abundant fibrous stroma

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

Genetics:   mutation in p53 tumor suppressor gene + k-ras gene

Peak prevalence:   7^th decade; M > F

Predisposed:   conditions causing chronic biliary inflammation

(1)   Inflammatory bowel disease (10 x increased risk); incidence of 0.4–1.4% in ulcerative colitis; latent period of 15 years; tumors usually multicentric + predominantly in extrahepatic sites; GB involved in 15% (simultaneous presence of gallstones is rare)

(2)   Biliary lithiasis: cholecystolithiasis (20–50%), hepatolithiasis (5–10%)

(3)   Primary sclerosing cholangitis (10–15%)

(4)   Infection with liver flukes: Opisthorchis viverrini and Clonorchis sinensis infestation (Far East)

◊  Most common cause worldwide!

(5)   Recurrent pyogenic cholangitis = hepatolithiasis

(6)   Viral infection: HIV, hepatitis B virus, hepatitis C virus, Epstein-Barr virus

(7)   Congenital biliary cystic disease: choledochal cyst / congenital hepatic cyst / congenital biliary atresia

(8)   Anomalous pancreaticobiliary junction

(9)   Ductal plate malformation:

›  Biliary hamartoma

›  Autosomal dominant polycystic disease

›  Congenital hepatic fibrosis

›  Caroli disease ← chronic biliary stasis

(10)   Papillomatosis of bile ducts

(11)   Choledochoenteric anastomosis

(12)   History of other malignancy (10%)

(13)   Toxins: thorotrast exposure, polyvinyl chloride

(14)   Heavy alcohol consumption

(15)   Alpha−1 antitrypsin deficiency

(16)   Familial polyposis

MR:

√  moderate peripheral enhancement followed by progressive centripetal enhancement

√  single / multifocal biliary strictures

√  focal / diffuse ductal thickening ± contrast enhancement

√  intraductal polypoid growth

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

Extrahepatic Cholangiocarcinoma

=  BILE DUCT CARCINOMA

Age peak:   6^th–7^th decade; M÷F = 3÷2

Incidence:   1÷100,000; < 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 carcinoma, epidermoid carcinoma, leiomyosarcoma

•  gradual onset of fluctuating painless jaundice

•  cholangitis (10%), weight loss, fatigability

•  intermittent epigastric pain, enlarged tender liver

•  elevated bilirubin + alkaline phosphatase

Growth pattern:

(1)  Infiltrating / sclerosing type (94%)

√  ductal wall thickening + sudden luminal obliteration

(2)  Papillary / tubular polypoid type (5–6%)

√  intraductal polypoid mass with irregular margin ± diffuse marked duct ectasia (mucin production)

UGI:

√  infiltration / indentation of stomach / duodenum

Cholangiography (PTC or ERC best modality to depict bile duct neoplasm):

√  prestenotic diffuse / focal biliary dilatation (100%)

√  progression of ductal stricture (100%)

√  frequently long / rarely short concentric focal stricture with irregular margins (in infiltrating type):

√  nipple / rattail termination

√  exophytic intraductal tumor mass (46%), 2–5 mm in diameter

US / CT:

√  mural thickening / small encircling mass of bile duct at point of obstruction (in 21% visible on US, in 40% visible on CT):

√  focal or diffuse stricture / complete obstruction of bile ducts

√  dilatation of intrahepatic ducts without extrahepatic duct dilatation

√  infiltrating tumor visible in 22% on CT as highly attenuating lesion, in 13% on US

√  exophytic tumor: visible on CT as hypoattenuating mass in 100%, in 29% on US

√  polypoid intraluminal tumor: visible on US as isoechoic mass within surrounding bile in 100%, in 25% on CT

√  regional lymph node enlargement

CECT:

√  hyperattenuating lesion at delayed imaging ← delayed accumulation + washout of fibrous center

MR:

√  hypointense relative to liver parenchyma on T1WI

√  hyperintense relative to liver parenchyma on T2WI

√  more conspicuous on fat-suppressed MR

Angiography:

√  hypervascular tumor with neovascularity (50%)

√  arterioarterial collaterals along the course of bile ducts associated with arterial obstruction

√  poor / absent tumor stain

√  displacement / encasement / occlusion of hepatic artery + portal vein

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:     periportal lymphangitic metastasis (no ductal dilatation, diffuse involvement of both sides of liver); sclerosing cholangitis, AIDS cholangitis, benign stricture, chronic pancreatitis, edematous papilla, idiopathic inflammation of CBD

Intrahepatic Cholangiocarcinoma

=  CHOLANGIOCELLULAR CARCINOMA

Frequency:   2^nd most common primary hepatic tumor after hepatoma; ⅓ of all malignancies originating in the liver; 8–13% of all cholangiocarcinomas

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

•  abdominal pain (47%); painless jaundice (12%)

•  palpable mass (18%), weight loss (18%)

◊  Biliary + vascular obstruction is typical!

√  ill-defined mass of 5–20 cm in diameter

√  satellite nodules in 65%

√  punctate / chunky calcifications in 18%

√  calculi in biliary tree

√  liver atrophy is suggestive although not specific

√  fibrotic pseudocapsule + secondary capsular retraction

US:

√  dilated biliary tree

√  predominantly solitary homo- / heterogeneous mass

√  hyperechoic (75%) mass for tumors > 3 cm

√  iso- / hypoechoic (14%) mass for tumor < 3 cm

√  mural thickening

√  peripheral hypoechoic tumor rim (35%) of compressed liver parenchyma

NECT:

√  single large predominantly homogeneous round / oval hypo- to isoattenuating dense mass with irregular margin

√  capsular retraction

√  stippled / punctate hyperattenuating foci (= hepatolithiasis)

√  dilatation of biliary tree peripheral to tumor

CECT:

√  hypoattenuating mass during arterial + portal venous phase

√  marked homogeneous delayed enhancement at 15 minutes (36–74%):

√  progressive concentric filling in of contrast medium (late) ← slow diffusion into interstitial tumor spaces within fibrous stroma

√  “peripheral washout” sign = (early) minimal to moderate thin rimlike / thick bandlike ragged enhancement around tumor:

√  clearing of contrast material in rim of lesion on delayed images

√  obliteration of portal vein + atrophy of involved segment

√  satellite nodules

MR:

√  large central heterogeneously hypo- to isointense mass on T1WI

√  variably hyperintense mass on T2WI depending on amount of mucinous material, fibrous tissue, hemorrhage, tumor necrosis:

√  hyperintense periphery (viable tumor) with irregular margin

√  large central hypointensity (fibrosis) on T2WI

√  hyperintense lesion on DWI ← suppression of high signal from vessels + bile ducts

√  ± DWI for small lesion

CEMR:

√  minimal / incomplete enhancement at tumor periphery on early images ← areas of early enhancement + rapid washout indicate active neoplastic growth

√  concentric centripetal internal fill-in = prominent progressive central enhancement on equilibrium / delayed phase ← vascular fibrotic stroma in tumor center

√  intense homogeneous enhancement during arterial phase + prolonged enhancement during delayed phase in smaller lesions with less fibrosis

√  satellite nodules in 10–20%

MR cholangiography:

√  localizing site of obstruction (100% accurate)

√  determining cause of obstruction (95% accurate)

Angiography:

√  avascular / hypo- / hypervascular mass

√  stretched / encased arteries (frequent)

√  neovascularity in 50%

√  lack of venous invasion

NUC:

√  cold lesion on sulfur colloid / IDA scans

√  segmental biliary obstruction

√  may show uptake on gallium scan

PET:

√  ring-shaped uptake ← excessive desmoplastic response of tumor center + neovascularity at tumor periphery

√  metastases to lymph nodes, liver, and distant sites

ERCP:

√  diagnostic bile sampling with cytologic analysis

√  biliary stent placement to relieve obstruction

Prognosis:  < 20% resectable; 30% 5-year survival

Intrahepatic Peripheral Cholangiocarcinoma

•  NO jaundice

Location:   right lobe predilection

√  solitary mass (nodular form) without hypoechoic halo

√  diffusely abnormal liver texture (infiltrative form):

√  tumor more hypoechoic if < 3 cm

√  tumor more hyperechoic if > 3 cm

√  well-marginated cystic mass (papillary mucin-producing tumor) ± diffuse hyperechoic flecks of tumor calcification

√  capsular retraction

√  delayed enhancement at 10 minutes

√  dilatation of bile ducts peripheral to tumor (31%)

√  tumor fingers in bile duct

DDx:  metastatic adenocarcinoma / leiomyosarcoma; sclerosing hepatocellular carcinoma

Klatskin Tumor

[Gerald Klatskin (1910–1986), pathologist in Yale, USA]

=  INTRAHEPATIC CENTRAL CHOLANGIOCARCINOMA = HILAR CHOLANGIOCARCINOMA

=  tumor at confluence of hepatic ducts (up to 50–70% of all cholangiocarcinomas)

Age:  > 65 years at presentation

Path growth pattern:   infiltrating (70%) / intraluminal polypoidal / mass-forming

•  abdominal pain, discomfort, anorexia, weight loss

•  pruritus, jaundice (late symptom)

√  direct signs of Klatskin tumor:

√  failure to demonstrate confluence of L + R hepatic ducts

√  iso- to hyperechoic central porta hepatis mass / focal irregularity of ducts (for infiltrating cholangiocarcinoma)

√  polypoid / smooth nodular intraluminal mass (for papillary + nodular types of cholangiocarcinoma) with associated mural thickening

√  indirect signs of Klatskin tumor:

√  segmental dilatation with nonunion of right + left ducts at porta hepatis + normal caliber of extrahepatic ducts

√  pressure effect / encasement / invasion / obliteration of portal vein and hepatic artery

√  lobar atrophy (14%) = dilated crowded ducts extending to liver surface ± geographic fatty change in one lobe

Rx:     > 50% inoperable at diagnosis ← advanced stage

Inoperability (CT and MR 75–93% accurate):

(1)  Invasion of right / left hepatic duct with extension to 2^nd-order biliary radicles

(2)  Atrophy of 1 hepatic lobe + involvement of contra- lateral portal vein branch / 2^nd-order biliary radicle

(3)  Vascular encasement / invasion of main portal vein or main hepatic artery

(4)  Metastatic disease: lymph node / distant

CHOLANGITIS

Acute Obstructive / Ascending Cholangitis

=  biliary duct obstruction associated with bacterial overgrowth

Cause:

(a)  benign disease:

1.   Stricture from prior surgery (36%) after bile duct exploration / bilioenteric anastomosis

2.   Calculi (30%)

3.   Sclerosing cholangitis

4.   Obstructed drainage catheter

5.   Parasitic infestation (liver fluke)

(b)  malignant disease:

1.   Ampullary carcinoma

Types:

(a)  Acute nonsuppurative ascending cholangitis

•  bile remains clear, patient nontoxic

(b)  Subacute nonsuppurative cholangitis

=  Cholangitis lenta = nonacute response of liver to systemic bacterial / fungal infection

◊  Important cause of liver failure + mortality with OLT

(c)  Acute suppurative ascending cholangitis (14%)

Associated with:   obstructing biliary stone or malignancy

•  biliary sepsis, CNS depression, lethargy, mental confusion, shock (50%)

√  purulent material fills biliary ducts

√  marked inhomogeneous hepatic parenchymal enhancement during arterial phase (60%)

Prognosis:  100% mortality if not decompressed; 40–60% mortality with treatment; 13–16% overall mortality rate

Organism:  E coli (31%), Klebsiella pneumoniae (17%), Enterococcus faecalis (17%), Streptococcus (17%)

•  recurrent episodes of sepsis + RUQ pain

•  Charcot triad (70%): fever + chills + jaundice

•  bile cultures in 90% positive for infection

√  may have gas in biliary tree

CECT:

√  nodular / patchy / wedge-shaped / geographic inhomogeneous transient hepatic parenchymal enhancement in periportal location on hepatic arterial phase (= hyperemic changes around bile ducts)

√  diffuse concentric thickening of extrahepatic bile ducts, often with enhancement

Cx:     miliary pyogenic hepatic abscesses; portal vein thrombosis; biliary peritonitis; secondary sclerosing cholangitis

Acute Bacterial Cholangitis

=  potentially life-threatening disease induced by acute biliary infection

Cause:    obstruction of CBD by stones (in up to 80%), malignancy (10–30%), sclerosing cholangitis, instrumentation of biliary tree (in 18% of transhepatic percutaneous biliary drainage catheter placement)

◊  Acute cholangitis occurs in 6–9% of patients admitted for gallstone disease

Related posts:

and Soft-Tissue Disorders Anatomy and Mammographic Technique Statistics and Function of Lung BREAST of the Nervous System

Stay updated, free articles. Join our Telegram channel

Join