Liver and intrahepatic bile duct - tumor

Last revised 9 April 2008

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Table of contents

Primary references

Benign tumors/conditions: angiomyolipoma, benign cystic mesothelioma, bile duct adenoma, biliary adenofibroma, biliary cystadenoma, biliary cyst, biliary papillomatosis, extramedullary hematopoiesis, fatty change, focal nodular hyperplasia, glomangioma, hemangioma, hemangiomatosis, hepatic vascular malformation with capillary proliferation, hepatocellular adenoma, hereditary hemorrhagic telangiectasia, heterotopia, inflammatory myofibroblastic tumor, intraductal papillary neoplasms, leiomyoma, lipoma, lymphangioma, mesenchymal hamartoma, myelolipoma, nodular regenerative hyperplasia, paraganglioma, perivascular epithelioid cell tumor, pseudocyst, pseudolipoma, reactive bile ductule proliferation, solitary fibrous tumor, solitary necrotic nodules

Dysplasia: liver cell dysplasia, borderline nodule, macroregenerative nodule

Hepatocellular carcinoma: general, cytology, variants: clear cell, fibrolamellar, oncocytic, pleomorphic, sarcomatoid, sclerosing, small

Leukemia/lymphoma: leukemia, lymphoma-general, lymphoma-primary, secondary, lymphoma subtypes: Burkitt’s, CLL/SLL, diffuse large B cell, follicular, hepatosplenic alpha-beta, hepatosplenic gamma-delta, Hodgkin’s, lymphoplasmacytic, MALT, nodal CD8+ cytotoxic peripheral T cell, splenic margin zone

Other malignancies: angiosarcoma, biliary cystadenocarcinoma, carcinoid, carcinosarcoma, Castleman’s disease, cholangiocarcinoma, congenital primitive epithelial tumor, epithelial myoepithelial carcinoma, epithelioid hemangioendothelioma, Erdheim-Chester disease, fibrosarcoma, follicular dendritic cell, gastrointestinal stromal tumor, germ cell tumors, hepatoblastoma, infantile hemangioendothelioma, juvenile xanthogranuloma, Kaposi’s sarcoma, Langerhans cell histiocytosis, leiomyosarcoma, liposarcoma, lymphoepithelioma-like carcinoma, malignant fibrous histiocytoma, malignant histiocytosis, mastocytosis, metastases, mixed hepatocellular carcinoma-cholangiocarcinoma, neuroendocrine carcinoma, reactive lymphoid hyperplasia, rhabdomyosarcoma, squamous cell carcinoma, undifferentiated sarcoma

Miscellaneous: staging, frozen section, grossing, features to report

 

Go to Liver and intrahepatic bile ducts - Non-tumor

 

Primary references

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AJCC Cancer Staging Manual (6th Ed)

American Journal of Surgical Pathology (AJSP), Jan 1999 to Feb 2004

Archives of Pathology and Laboratory Medicine (Archives), Jan 1999 to Apr 2004

Human Pathology, Jan 1999 to Mar 2004

Modern Pathology, Jan 1999 to Mar 2004

Rosai, J:  Ackerman’s Surgical Pathology (8th Ed); Mosby-Year Book, Inc., 1996

Sternberg, S: Diagnostic Surgical Pathology (3rd Ed); Lippincott Williams & Wilkins, 1999

Loyola University textbook

USCAP short course: Mod Path 2000;13:679

Journal search terms: liver, hepatic

 

Please refer to these primary references for more detailed discussions

 

Benign tumors

Angiomyolipoma (AML)

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<100 cases reported; often misdiagnosed

Mesenchymal tumor arising from perivascular epithelioid cells; also lymphangioleiomyomas, clear cell sugar tumors of lung, rare myomelanocytic tumors

Similar histologically to renal angiomyolipoma

Mean age 50 years, range 9-79 years; 80% women

Only 6-10% associated with tuberous sclerosis, these cases are associated with renal AML and may be multiple

Myoid and vascular components are clonal; adipose tissue component may be reactive

Case report of 15+ tumors in 46 year old woman without tuberous sclerosis (Mod Path 2002;15:167)

MRI image : multiple hypointense lesions

Gross: well circumscribed, solitary masses up to 20 cm, yellow-gray-white; necrosis present in larger tumors, background liver is normal

Gross images : multiple well circumscribed lesions

Micro: mature adipose tissue, smooth muscle cells and thick walled blood vessels with spindle cells radiating from walls; extramedullary hematopoiesis (40%); smooth muscle cells are epithelioid or spindled with clear or eosinophilic cytoplasm; mast cells common; occasional features are cellularity, nuclear pleomorphism with intranuclear inclusions, tumor giant cells; no/rare mitotic figures; unusual subtypes are oncocytic and trabecular

Micro images: H&E and stains

Micro images : low power, epithelioid tumor and smooth muscle actin

Positive stains: HMB45, MelanA/MART-1, microphthalmia transcription factor (50%), S100, smooth muscle actin, desmin, c-kit/CD117 (all cell types)

Negative stains: cytokeratin

EM: epithelioid myoid cells have premelanosomes, numerous mitochondria, abundant rough endoplasmic reticulum, glycogen, tight junctions and basal lamina, but no thick filaments

References: AJSP 2002;26:493 (c-kit staining), Archives 2002;126:49 (melanoma markers), AJSP 1999;23:34 (review)

 

Benign cystic mesothelioma

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Also called multilocular peritoneal inclusion cyst

Very rare in liver; elsewhere usually young women with local recurrence

Benign, indolent, slowly progressive, curable

Laboratory: elevated CA 19-9 in serum and cyst fluid

Case reports: 58 year old Italian man with elevated CA 19-9, multiple benign appearing liver cysts and single cysts in kidney and pancreas (Archives 2001;125:944), 51 year old woman (AJSP 2002;26:1523)

Treatment: excision, but may recur

Gross images: cyst before and after aspiration

Micro: well encapsulated, partially cystic, highly vascular; no cirrhosis; loose cords of tumor cells separated by medium to large vessels with walls of varying thickness; cystic spaces lined by tumor cells, either epithelioid or with hobnail appearance

Micro images: H&E, EM, CA 19-9, CEA, CA 125

Positive stains: CK 8/18 (CAM 5.2), calretinin, EMA, vimentin, estrogen receptor

DD: hydatid cyst, biliary cystadenoma, serous cystadenoma, cystic neoplasms

 

Bile duct adenoma

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Incidental finding, although often confused with adenocarcinoma

Usually adults > 40 years old, no gender preference

Benign

Much less common than bile duct hamartoma

Gross: well-circumscribed but unencapsulated, firm, gray-white, tan, subcapsular nodules; 85% solitary; usually 5 mm or less but 7% are larger than 1 cm; may have central depression

Micro: compact network of simple tubular ducts or more complex tortuous arrangement, with small or indistinct lumina; epithelium has abundant cytoplasm and pale nuclei compared to interlobular bile ducts in adjacent liver; variable fibrous stroma, granulomas, calcification, inflammatory cells; usually no cystic change, no cytoplasmic or intraluminal bile, no atypia, no mitotic figures, no angiolymphatic invasion

Positive stains: mucin (intracytoplasmic), CEA, EMA, keratin, PAS highlights basement membrane

DD: cholangiocarcioma, adenocarcinoma

 

Atypical clear cell type

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Rare; ages 25-64 years in 3 cases described

Incidental finding

Gross: 1 cm, subcapsular

Micro: bile duct tumor composed almost entirely of small nests and tubules of clear cells infiltrating hepatic parenchyma; small nests surrounded by PAS+ membrane (may represent tubular structures); well defined cytoplasmic borders, mild nuclear hyperchromasia, mild stromal sclerosis; no mitotic activity

Positive stains: CK7, EMA, CEA, p53, mucin (focal)

Negative stains: CK20, vimentin, HepPar1, chromogranin, Ki-67 (<10% positive)

DD: well differentiated adenocarcinoma, metastatic renal cell carcinoma, clear cell cholangiocarcinoma (larger, tubular pattern, desmoplastic stroma, more nuclear atypia and mitotic activity; similar immunostains results)

References: AJSP 2001;25:956

 

Biliary adenofibroma

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Extremely rare (< 5 reported cases)

Case report in 47 year old woman, AJSP 2003;27: 693

Appears to originate from interlobular or larger bile ducts

Benign behavior to date, but may be premalignant

Micro: (a) microcystic and tubular structures lined by low columnar/cuboidal epithelium and (b) dense fibrous stroma with spindle cells displaying mild nuclear pleomorphism; no/rare mitotic figures, no stromal invasion

Positive stains: epithelium - AE3, CAM5.2, CK 7, CK9, CEA, EMA, D10, p53

Negative stains: Alcian blue, vimentin, desmin

DD: von Meyenburg complex (smaller, usually multifocal, but similar staining pattern)

 

Biliary cystadenoma

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5% of all hepatic solitary cysts

95% occur in women, mean age 45 years (range 2-87 years)

84% are intrahepatic, also in common bile duct (6%), hepatic ducts (4%), cystic duct (4%), gallbladder (2%)

Associated with polycystic liver disease, abnormal hepatobiliary anatomy

Usually slow growing with good prognosis after surgical excision, although 25% have coexisting malignancy

Complications: intracystic hemorrhage, bacterial infection, rupture

Also associated with borderline or malignant lesions

Laboratory: elevated CA 19-9 (in cases with ovarian type stroma) and CEA in cyst fluid and serum

Xray: calcification in 20% (resemble echinococcal cyst)

Treatment: complete excision (rarely has delayed recurrence)

Case reports: Case of the Week #70, tumor arising from left hepatic duct (Archives 2001;125:1507), encased in smooth muscle tumor (AJSP 1999;23:854), 39 year old woman with abdominal pain (World J Gastroenterol 2006;12:6062)

Gross: encapsulated, solitary, mean 15 cm (range 3-28 cm), usually mucinous, multilocular by definition (locules have varied sizes); contains up to several liters of fluid; smooth inner surface with few trabeculations or polypoid cystic projections; rarely contains gallstones; nodules of solid tissue suggests malignancy

Gross images: large, smooth lined cyst

Micro: mucinous - lined by single layer of columnar-cuboidal mucinous epithelium with basal nuclei and apical mucin; spindle-cell ovarian type stroma only in women (resembles pancreatic mucinous cystic neoplasms); spindle cells may contain fat and smooth muscle; may have collagenous zone above stroma (resembling collagenous colitis); capsule composed of dense collagen with blood vessels, variable bile ducts; may have squamous or intestinal metaplasia, often neuroendocrine cells; may have dysplastic or borderline foci; may have ulceration with macrophages containing lipofuscin or hemosiderin, cholesterol clefts with foreign body giant cell reaction or calcification; no/rare atypia, no/rare mitotic figures

serous - lined by bland, flat to cuboidal cells with clear, glycogen-rich cytoplasm, no spindle cell stroma; no mucin; may represent hepatic metastasis from pancreatic serous cystadenocarcinoma

Micro images: image #1-low power#2-low power#3-high power#4-high power#5-high power#6-high power#7-high power#8-CA19-9#9-progesterone receptor 

Positive stains: epithelial cells - cytokeratin, EMA, CEA, CA19-9; stromal cells - muscle specific actin, vimentin; usually ER and PR (Dig Dis Sci 2006;51:623)

DD: borderline tumors (have high grade dysplasia and complex architecture), invasive tumors (put through numerous sections to exclude)

 

Borderline

Tumors with high grade dysplasia with complex architecture

 

Biliary cyst

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Micro: lined by cuboidal or biliary type epithelium; rarely squamous lined; thin fibrous wall

 

Biliary papillomatosis

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Rare, 50 cases reported

2/3 men, usually ages 40+ years

Multiple papillary adenomas extensively throughout intra- or extrahepatic biliary tract

Often recurs, 25% have malignant transformation, but only rare metastases (to lung)

Associated with Caroli’s disease, choledochal cyst, polyposis coli and ulcerative colitis

Most patients die within 3 years due to cholangitis and hepatic failure

Case report in 66 year old man with cirrhosis due to Hepatitis C and malignant transformation, Archives 2002;126:369

Treatment: difficult to treat because multifocal; liver transplant may be helpful

Gross: inner surface of ducts has velvety papillary growths with masses filling dilated ducts; masses are soft, friable, white-red-tan

Micro: dilated ducts contain multiple papillary tumors composed of fibrovascular cores lined by columnar, pseudostratified, biliary-type cells with numerous cytoplasmic mucin vacuoles; tumor may be solid or cribriform; varying cytologic atypia and mitotic activity; may have associated tubular adenocarcinoma with invasion

Micro images: fibrovascular cores and invasive disease (in case report above)

 

Extramedullary hematopoiesis

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Usually asymptomatic or associated with anemia; rarely presents as a liver mass

Case report of 52 year old woman with 2.5 cm, 5 cm and 7 cm liver masses and normal serum AFP, Archives 2003;127:631

Treatment: radiation or hydroxyurea if symptomatic

Micro: erythroid precursors in sinusoids (resemble lymphocytes), myeloid precursors in portal tracts (resemble mixed portal infiltrate or eosinophils in neonates); also megakaryocytes within sinuses

Cytology images: Diff-Quick (2), Pap stain

 

Fatty change

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Not neoplastic, but simulates lipomatous tumor

Associated with obesity, diabetes, alcohol abuse, dyslipidemia

Stable or regresses if underlying condition improves

Gross: subcapsular yellow-white foci, often multiple, up to 10 cm

Micro: diffuse or focal steatosis adjacent to unremarkable liver, may have foreign-body type granulomatous inflammation

 

Focal nodular hyperplasia (FNH)

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Common (#2 liver tumor after hemangioma)

Mass lesion of young (median age 38 years); some studies show female predominance

Represents 2-10% of pediatric hepatic tumors

May be associated with oral contraceptives (66-95% of cases), hepatic cavernous hemangioma (20%), glycogen storage disease type Ia, portal hypertension

Tumors associated with oral contraceptives often have hemorrhage, necrosis, infarction

Usually an incidental finding; present in 1% of autopsies

May have abdominal discomfort, pain, anorexia or fatigue (Hepatobiliary Pancreat Dis Int. 2004;3:199)

May represent hyperplastic response to arterial malformation or other vascular anomaly; is NOT a neoplasm (Am J Gastroenterol 2006;101:2341)

Case reports: Case of the Week #88

Xray: mass with central scar, centrifugal hypervascularity by angiography; CT and MRI are important, but often cannot make a definite preoperative diagnosis (Hepatobiliary Pancreat Dis Int. 2007;6:52)

Treatment: excellent prognosis; adult women should discontinue oral contraceptives, if applicable; surgery if symptomatic, complications, compression of adjacent organs or lesion progression (Eur J Pediatr Surg 2006;16:235)

Gross: well-demarcated, subcapsular, light brown to yellow (lighter than surrounding liver); bulging nodule, 70-80% solitary, up to 5 cm; rarely > 10 cm; has central gray-white stellate scar (unless < 1 cm) from which fibrous septa radiate to periphery and create multiple smaller nodules; hemorrhage, necrosis, infarction, bile staining often seen; larger tumors may have multiple scars; adjacent liver is normal

Gross images: well circumscribed mass with central stellate scar #1#2

Micro: hepatocyte nodules are surrounded by fibrous septa with large malformed arterial branches not accompanied by interlobular bile ducts or portal veins; septal margins have foci of intense lymphocytic infiltrates and marked bile duct proliferation with histologic changes of chronic cholestasis (Mallory’s hyaline, bile pigment, copper deposits, pseudoxanthomatous change), variable neutrophilic infiltration; ductules appear to arise from limiting plate; central scar contains central fibrous body with tortuous large vessels with fibromuscular hyperplasia and luminal narrowing; hepatic plates are 1-2 cells thick, similar to surrounding liver, but may be larger and paler with fat or glycogen; no atypia, no mitotic figures; telangiectatic variant has multiple dilated vascular channels in center of mass

Most tumors (80%) have the 3 classic features of abnormal architecture, bile ductular proliferation and malformed vessels.  Non-classic forms lack either abnormal architecture or malformed vessels, and are divided into three types - (a) telangiectatic, (b) mixed hyperplastic and adenomatous or (c) atypia of large cell (AJSP 1999;23:1441)

Telangiectatic FNH is considered by some to be a variant of hepatocellular adenoma (World J Gastroenterol 2007;13:2649) 

Micro images: fibrous area with blood vessels and bile ductules #1#2#3associated with fibrolamellar carcinomadiagram of possible pathogenesis

Positive stains: alpha-1-antitrypsin

Negative stains: p53, CD143 (angiotensin I-converting enzyme: reduced expression, AJSP 2004;28:84)

DD: Osler-Weber-Rendu disease, Budd-Chiari syndrome or cirrhosis (adjacent liver is not normal), fibrolamellar hepatocellular carcinoma (marked atypia of hepatocytes), hepatocellular adenoma (encapsulated, monoclonal), peritumoral hyperplasia (Archives 2000;124:1105)

References: Radiographics 2004;24:3, eMedicine

 

Multiple focal nodular hyperplasia syndrome

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Multiple FNH lesions plus one other lesion: either hepatic hemangioma, arterial dysplasia, Klippel-Trenaunay-Weber syndrome, brain telangiectasia, berry aneurysm, astrocytoma or meningioma

Micro: often telangiectatic variant with multiple dilated vascular channels in center of mass

 

Glomangioma

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Rare, <10 cases reported

Type of glomus tumor (neoplasm of glomus apparatus) with prominent vascular structures

Case report in 57 year old man with flank pain and 3 cm liver mass, Archives 2004;128:e46

Xray images: hypervascular mass

Micro: small to medium branched vessels with stroma containing small, round regular cells with sharply outlined round/oval nuclei

Micro images: small bland tumor cells in vascular network, smooth muscle actin and CD34

Positive stains: vimentin, smooth muscle actin, CD34, calponin (focal)

Negative stains: desmin, S100, chromogranin, CD117

 

Hemangioma

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Most common primary hepatic tumor

Usually an incidental finding, found in 1% of routine autopsies and 20% of autopsies with extensive investigation

More common in adults than children, 75% in women, who are more likely symptomatic

10% enlarge with follow-up, may be related to pregnancy or oral contraceptives

Associated with multiple focal nodular hyperplasia syndrome

Giant cavernous hemangiomas (> 4-10 cm) only rarely rupture

Fibrotic tumors may be precursor of solitary necrotic nodules

Solitary capillary hemangiomas are extremely rare

Treatment: excision or observation (may involute)

Gross: solitary (70-90%), usually 2-4 cm, although tumors up to 20 cm are overrepresented in studies of excisions; soft, red-purple, well circumscribed; subcapsular or deep; collapse when sectioned as blood oozes out

Gross images: well circumscribed mass

Micro: variably sized vascular spaces lined by flat endothelial cells and myxoid or fibrous stroma; large fibrous septa may trap bile ducts; variable thrombosis, calcification, phleboliths; increased fibrosis with age of lesion may obliterate lumen

Micro images: cavernous hemangioma #1, #2

Positive stains: elastin and trichrome may expose vessels in old fibrous lesions

DD: peliosis hepatis (no fibrous septa), hereditary hemorrhagic telangiectasia (aberrant portal vessels, dilated vascular channels within portal tracts), hemangiomatosis, infantile hemangioendothelioma (atypia present, although not necessarily everywhere)

 

Hemangiomatosis

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Also called diffuse hemangiomatosis

Rare disease of adults

May also affect lung and bone

Gross: nodules may replace entire liver

Micro: numerous small, poorly circumscribed, hemangiomatosis nodules in portal tracts, may become sclerosed

 

Hepatic vascular malformation with capillary proliferation

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Usually symptomatic at birth

Congenital vascular malformation

Does not regress spontaneously

Symptoms: abdominal mass or distention, cardiomegaly, congestive heart failure, anemia, thrombocytopenia, DIC, fever, jaundice, elevated serum AFP

Treatment: lobectomy; good outcome

Gross: single large mass, mean 8 cm, range 5-11 cm; central infarction and hemorrhage is common

Micro: outer dilated vessels lined by flattened endothelium and loose myxoid stroma; central infarction and hemorrhage

DD: infantile hemangioendothelioma (GLUT1+, Hum Path 2004;35:200)

 

Hepatocellular adenoma

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Also called liver cell adenoma

Arises in normal or nearly normal liver in patients with abnormal hormonal or metabolic condition

95% women, usually child-bearing age (very rare in children), history of 5+ years of oral contraceptives in 85% (occasionally regress after discontinuation); also associated with anabolic steroids (in men), anti-estrogens, Klinefelter’s syndrome or other abnormal secretion of sex steroids

Also associated with glycogen storage disease types Ia and III, Fanconi’s anemia, familial adenomatous polyposis, familial diabetes mellitus, Hurler’s disease or tyrosinemia; also spontaneous

2-4% of hepatic tumors in children

Subcapsular tumors may rupture, particularly during pregnancy

Benign, but may contain hepatocellular carcinoma or cause severe hemorrhage

10% or lower risk of hepatocellular carcinoma if not resected; definite risk in young men with glycogen storage disease type Ia

Must sample generously to rule out coexisting hepatocellular carcinoma

May contain hepatic progenitor cells, AJSP 2001;25:1388

Laboratory: normal liver function tests, may have elevated alpha fetoprotein

Hepatocellular adenomatosis: 10+ tumors

Treatment: excision

Case reports: tumor in 9 year old girl with later fibrolamellar carcinoma (Archives 2004;128:222)

Gross: solitary (70%, anabolic steroid related more often multiple), pale, yellow-tan (different from surrounding liver), frequently bile-stained nodules, often subcapsular, 10-30 cm, sharply demarcated or encapsulated; usually right lobe, may be pedunculated (10%); may have hemorrhagic, necrotic or infarcted foci; usually no fibrous septa or central scar; adjacent liver is noncirrhotic

Gross images: well circumscribed lesion #1, #2

Micro: sheets and cords 1-3 cells thick of normal appearing hepatocytes with variable glycogen; no/rare mitotic figures; no portal tracts, no central veins or connection with biliary system but see prominent “free floating” arterial vessels and draining veins throughout the tumor; intact reticulin framework; pseudoglands may be present; may have cytoplasmic globules (PAS+, diastase resistant, alpha-1-antitrypsin+, AFP-), 10% have multinucleation, but no atypia, no prominent nucleoli, no intranuclear vacuoles, no/rare mitotic figures, no angiolymphatic invasion, no/rare extramedullary hematopoiesis, no epithelioid granulomas, no decreased reticulin framework; degenerative changes include dilated sinusoids, blood filled (pelioid) spaces, myxoid stroma, focal necrosis, infarction, hematoma; rarely contains abundant fat, oncocytic changes, Mallory’s hyaline, granulomatous inflammation

Micro images: adenoma #1, #2 in 14 year old (figures a-d), ER and PR

Positive stains: ER, PR

Negative stains: p53

DD: hepatocellular carcinoma (mitotic activity, atypia, trabecular growth, cell plates > 2 cells thick, vascular invasion, infiltrative, often different clinical features), focal nodular hyperplasia (central stellate scar and radiating fibrous septa)

References: Hum Path 2002;33:852 (childhood tumors with beta catenin abnormalities)

 

Atypical hepatocellular adenoma

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Androgen related tumors that regress with androgen withdrawal

Only rarely metastasize

Micro: marked pleomorphism with prominent nucleoli and extensive pseudoglands, resembling hepatocellular carcinoma, but no trabecular pattern, low N/C ratio, no vascular invasion

DD: hepatocellular carcinoma (elevated serum AFP, cirrhosis, vascular invasion, high N/C ratio, trabecular pattern), focal nodular hyperplasia (central scar), hepatoblastoma (elevated serum AFP, age < 3 years, no metabolic disease, light and dark cytoplasmic pattern, small cell size)

 

Pigmented liver cell adenoma

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Black pigment present

Case reports in 2 men without Dubin-Johnson syndrome, AJSP 2000;24:1429

Micro: pigment granules are larger and darker than lipofuscin; no portal tracts, bile ducts or ductules within the tumor

Positive stains: Masson-Fontana (for melanin and Dubin-Johnson pigment)

DD: well differentiated hepatocellular carcinoma

 

Hereditary hemorrhagic telangiectasia

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Also called Osler-Weber-Rendu syndrome

Autosomal dominant; systemic fibrovascular dysplasia; prevalence of 10-20 per 100,000 population

Caused by HHT1 (encodes endoglin on #9, expressed in central vein endothelium of normal liver) and HHT2 (encodes activin receptor-like kinase 1 / ALK1 on #12)

Hemorrhage, telangiectasia and arteriovenous malformations of vessels in skin, mucous membranes, lung, liver (up to 33%), CNS

Usually asymptomatic

May have hepatic vascular shunts that may cause high output congestive heart failure, portovenous shunts that cause hepatic encephalopathy or arterioportal shunts that cause portal hypertension

Case reports: 56 year old woman with pulmonary hypertension and intractable pulmonary bleeding (due to pulmonary capillary hemangiomatosis) and GI bleeding, Hum Path 2004;35:266

Gross: telangiectatic lesions throughout the liver

Gross images: dilated and thickened hepatic artery branches

Micro: focal sinusoidal ectasia, abnormal direct communications between hepatic arterial branches and ectatic sinusoids (AV shunts), frequent and large communications between portal and central veins through ectatic sinusoids (portovenous shunts)

Micro images: dilated arteries, vein and sinusoids, three dimensional reconstruction

References: Archives 2001;125:1219

 

Heterotopia

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Usually from pancreas, adrenal gland or spleen

Pancreas: 4% of autopsies, usually within large and medium sized portal tracts; acinar cells but no islets

Adrenal gland rests: rare, may be confused with renal cell carcinoma or other clear cell carcinomas

Heterotopic liver is not connected to main liver; is found in gallbladder, spleen, pancreas, umbilicus, adrenal gland, small intestine, lesser omentum, lung

 

Inflammatory myofibroblastic tumor

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Also called inflammatory pseudotumor

Uncommon

Mean 37 years but all ages, 75% male

Associated with occlusive phlebitis and chronic cholangitis

Rarely associated with sarcoma or follicular dendritic cell tumor

In extrapulmonary tumors, recurs locally in 25%; 8% metastasize

Symptoms: fever, upper abdominal pain

Treatment: excision, occasionally regresses spontaneously

Gross: well circumscribed, solitary (70%), 1-25 cm, variegated cut surface, may extend into vena cava or soft tissue

Micro: plasma cells, lymphocytes, neutrophils, macrophages, mast cells and myofibroblast-like spindled cells in varying amounts, in whorled, fibrotic stroma; occasional myxoid areas, minimal vascular component; minimal pleomorphism, no/rare mitotic activity; rarely is highly cellular or has mitotic activity (often in children)

Positive stains: vimentin (>90%), smooth muscle actin (80%), muscle specific actin (80%), desmin (40%), CD68 (40%), pankeratin (30%), p53 (30%), ALK1

Negative stains: S100, CD21, myoglobin

DD: sclerosing hemangioma, leiomyoma, solitary fibrous tumor, follicular dendritic cell tumors (CD21+, CD35+), Hodgkin’s lymphoma (stromal cells CD15+, CD30+), organizing abscess, postoperative spindle cell nodule, spindle cell carcinoma or sarcoma

 

Intraductal papillary neoplasms of biliary tract

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Uncommon

Solitary or may spread along biliary tree to cystic duct or duodenal papilla

May resemble intrapapillary mucinous neoplasms of pancreas as both arise within a dilated duct system and demonstrate predominantly intraductal growth

Risk factor for cholangiocarcinoma, biliary obstruction, recurring ascending cholangitis

Often are carcinomas

Micro: papillary fronds with fine vascular cores; epithelial cells are either biliary type or have gastric or intestinal differentiation with goblet cells and Paneth cells; production of extracellular intraductal mucin less common than pancreatic IPMNs

Borderline tumors: mild to moderate nuclear atypia and nuclear pseudostratification limited to basal 2/3 of the epithelium

Carcinomas: severe cytological atypia, loss of nuclear polarity or architectural cribriforming / papillary fusion is present

Negative stains: p53, CK20

Molecular: Kras activating mutations (29%), 18q- (31%) but no loss of DPC4

References: Hum Path 2003;34:902, Hum Path 2002;33:503 (stains)

 

Leiomyoma

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Solitary nodule that may resemble metastatic well differentiated leiomyosarcoma

May be associated with HIV, EBV

 

Lipoma

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Rare, usually incidental finding

Gross: solitary, 1-20 cm

Micro: mature fat or brown fat (hibernoma)

DD: angiomyolipoma, focal fatty change

 

Lymphangioma

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