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Liver and intrahepatic bile ducts - tumor

Other malignancies

Undifferentiated embyronal sarcoma

Reviewers: Deepali Jain, M.D. (see Reviewers page)
Revised: 9 January 2013, last major update February 2012
Copyright: (c) 2004-2013, PathologyOutlines.com, Inc.


● Also called malignant mesenchymoma, mesenchymal sarcoma
● 9-15% of pediatric hepatic tumors (#3 after hepatoblastoma and hepatocellular carcinoma) - usually ages 6-10 years
● In children, often associated with mesenchymal hamartoma (Pediatr Dev Pathol 2011;14:111), rarely with vaginal embryonal rhabdomyosarcoma (Ann Diagn Pathol 2011;15:250)
● Rare in adults (Cancer 2008;112:2274)
● Appears to be a primitive mesenchymal neoplasm with possible foci of differentiated sarcoma, such as angiosarcoma
● Typically presents with pain, fever, abdominal mass and normal serum AFP (J Pediatr Surg 2008;43:1912)
● Good prognosis (Cancer 2002;94:252), but large tumors may rupture and cause death (J Pediatr Hematol Oncol 2007;29:63)


● Complete resection and chemotherapy (J Gastrointest Surg 2007;11:73), possibly liver transplant (J Pediatr Hematol Oncol 2012 Nov 6 [Epub ahead of print])

Case reports

● 10 year old girl with abdominal pain and anorexia (Case of the Week #134)
● 16 year old girl with palpable liver mass, fever and vomiting (Arch Pathol Lab Med 2003;127:e163)
● 74 year old woman with tumor arising from mesenchymal hamartoma (Int J Surg Pathol 2012;20:297)(

Gross description

● 10-30 cm, solitary, well-demarcated, soft tumor with cystic, gelatinous, hemorrhagic and necrotic foci

Gross images

10 year old girl with 15 cm tumor

Adult with 16 cm tumor

Micro description

● Variably cellular tumor with anaplastic, spindled / oval cells with prominent hyaline globules and ill-defined borders within pseudocapsule
● Nuclei have stippled chromatin, inconspicuous nucleoli
● Variably myxoid stroma with numerous thin-walled veins
● Also bizarre tumor cells with prominent eosinophilic cytoplasm and PAS+ diastase resistant hyaline globules
● Extramedullary hematopoiesis common, frequent mitotic activity
● Note that trapped hepatocytes and bile-duct structures are present at periphery
● Adults may have partial smooth muscle differentiation (Hum Pathol 2003;34:246)

Micro images

Case of the Week #134

Left to right: PAS diastase, alpha-1-antitrypsin

Adult with adipophilin-positive vesicles

Adult with 16 cm tumor

Positive stains

● PAS+ diastase resistant hyaline globules, vimentin, high Ki-67 index (Appl Immunohistochem Mol Morphol 2006;14:193)
● Glypican-3 (60%, Hum Pathol 2012;43:695), CD56, paranuclear dot-like CK, Bcl-2, alpha-1 antitrypsin and alpha-1 antichymotrypsin, variable muscle markers

Negative stains

● Alpha fetoprotein (hyaline globules), keratin, myogenein

Electron microscopy description

● Hyaline globules are lysosomal and possibly apoptotic bodies

Differential diagnosis

Embryonal rhabdomyosarcoma: usually 2-6 years old, myxoid mass extending into bile duct, rhabdomyoblastic differentiation with cytoplasmic cross striations, cambium layer present, no diffuse anaplasia or hyaline globules, myogenin+ and myoD1+ (Pediatr Dev Pathol 2007;10:89)
Gastrointestinal stromal tumor: adults, CD117+, DOG1+, CD34+ (usually)
Hepatoblastoma, mixed form
● Hydatid cyst in endemic areas (J Pediatr Surg 2008;43:E1)
Mesenchymal hamartoma: usually < 1 year old, cystic, bland tumor cells and no giant cells
Sarcomatoid hepatocellular carcinoma
Sclerosing variant of hepatocellular carcinoma: rare in children, has intracellular bile, Mallory-Denk bodies, HepPar1+

End of Liver and intrahepatic bile ducts - tumor > Other malignancies > Undifferentiated embryonal sarcoma

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