Case 3 -
Abbott Northwestern Hospital
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Thirty-six year old woman presented with upper abdominal fullness and acute onset of right upper quadrant pain. Ct scan showed a 10 cm complex cystic and solid mass with hemorrhage in posterior right hepatic lobe.
Embryonal sarcoma is an uncommon malignancy which originates exclusively in the liver and primarily in
pediatric patients. Case report publications have documented several dozen adult cases. Embryonal
sarcoma is also variably referred to as "undifferentiated embryonal sarcoma" and "undifferentiated
(embryonal) sarcoma". Original reports used the term "malignant mesenchymoma" of the liver, but the
current terminology became entrenched following an article entitled, "Undifferentiated (embryonal)
sarcoma of the liver: report of 31 cases." By Stocker and Ishak at the AFIP.  The above paper noted
highest incidence among 6 to 10 year- old children. A more recent publication from the Childrens
Oncology Group showed the median age to be 10.5 years.  Embryonal sarcoma is the third most common
primary hepatic malignancy in children, after hepatoblastoma and hepatoma, accounting for approximately
10-15% of pediatric liver malignancies.  Presentation includes overt abdominal mass and pain, sometimes
associated with tumor hemorrhage.
Pathological/Microscopic Findings and any Immunohistochemical or Other Studies:
Embryonal sarcoma typically forms a large, single, well- demarcated, gelatinous mass in a
non-cirrhotic liver. Cystic areas, necrosis and areas of intratumoral hemorrhage are common.
microscopic features are very characteristic, consisting of primitive-appearing stellate and spindled
cells in a myxoid background. The tumor cells are pleomorphic and hyperchromatic. A minority of tumor
cells contain variably-sized, eosinophilic, diastase-resistant cytoplasmic inclusions. Mitotic activity
is usually brisk. This histologic constellation is distinctive and typically leaves little doubt about
the diagnosis if the microscopist is familiar with this entity.
The differential diagnosis includes other sarcomas and sarcomatoid malignancies, including biliary
rhabdomyosarcoma, leiomyosarcoma, angiosarcoma, and germ cell tumors with immature teratomatous or
Sarcomatoid differentiation of a primary hepatic carcinoma and metastatic
sarcomas are also differential considerations. Given the distinctive histologic features noted above,
the most confusing issue with this differential diagnosis is likely the name similarity between embryonal
sarcoma and embryonal rhabdomyosarcoma. In addition to the very different histologic features, embryonal
rhabdomyosarcoma is positive for myogenin and MyoD1 expression by immunohistochemistry while hepatic
embryonal sarcoma is negative for these markers. 
With regards to the remainder of the differential diagnosis, Kiani, et al, has detailed the
immunoprofile of embryonal sarcoma. All cases stained with vimentin, and all cases were negative for
hepatocyte antigen, myogenin, CD34, SMMS, h-caldesmon, PE10, ALK-1, S100 and cytoplasmic c-kit. In a
minority of cases, focal immunostaining was observed with cytokeratin AE1/AE3, CD10, calponin, desmin and
p53. It appears very likely that there is a relationship between mesenchymal hamartoma, a rare benign
childhood tumor which typically presents in the first 1 to 2 years of life, and embryonal sarcoma.
Several studies have documented areas of mesenchymal hamartoma in the background of a minority of
childhood embryonal sarcomas.
Cases of both embryonal sarcoma and mesenchymal hamartoma have
demonstrated specific karyotypic abnormalities involving 19q13.4.  No other characteristic chromosomal
or molecular abnormality has been demonstrated in embryonal sarcoma.
Review of the Literature/Treatment Options (if applicable):
The early literature on embryonal sarcoma indicated a devastating prognosis, with median survival less
than one year.  While this is clearly an aggressive and dangerous tumor, multimodality therapeutic
approaches which include both surgery and chemotherapy have prolonged median survival and resulted in
some sustained responses.
Successful treatment has been documented even in cases of ruptured
embryonal sarcoma.  In a 2007 publication from Loma Linda University Medical Center and Children's
Hospital, two patients were treated with: Patient 1- adjuvant cycles of cisplatin and adriamycin
alternating with a combination of vincristine, ifosfamide, and etoposide; Patient 2- neoadjuvant
chemotherapy consisting of alternating cycles of cyclophosphamide, mesna, vincristine, and actinomycin,
with cycles of ifosfamide and VP-16. 
In summary, embryonal sarcoma is an uncommon, but aggressive liver malignancy which present
predominately in children. The histologic findings are distinctive. A minority of the tumors arise in
association with mesenchymal hamartoma, with which it shares karyotypic abnormalities at 19q13.
Treatment with combination of complete resection combined with chemotherapy has resulted in improved
- Stocker JT, Ishak KG: Undifferentiated (embryonal) sarcoma of the liver: report of 31 cases. Cancer 1978;42:336-348.
- Nicol K, Savell V, Moore J, et al, with the Children's Oncology Group, Soft Tissue Sarcoma Committee. Distinguishing undifferentiated embryonal sarcoma of the liver from biliary tract rhabdomyosarcoma: a Children's Oncology Group study. Pediatr Dev Pathol 2007;10:89-97.
- Baron PW, Majlessipour F, Bedros AA, et al. Undifferentiated embryonal sarcoma of the liver successfully treated with chemotherapy and liver resection. J Gastrointest Surg 2007;11:73-5.
- Lenze F, Birkfellner T, Lenz P, et al. Undifferentiated embryonal sarcoma of the liver in adults. Cancer 2008; 112:2274-82.
- Kiani B, Ferrell LD, Qualman S, Frankel WL. Immunohistochemical analysis of embryonal sarcoma of the liver. Appl Immunohistochem Mol Morphol 2006;14:193-7.
- Shamseddine A, Faraj W, Mukherji D, et al. Unusually young age distribution of primary hepatic leiomyosarcoma: case series and review of the adult literature. World J Surg Oncol 2010;8:56.
- Xu AM, Gong SJ, Song WH, et al. Primar mixed germ cell tumor of the liver with sarcomatous components. World J Gastroenterol 2010;16:652-6.
- Siddiqui MA, McKenna BJ. Hepatic mesenchymal hamartoma: a short review. Arch Pathol Lab Med 2006;130:1567-9.
- Cook JR, Pfeifer JD, Dehner LP. Mesenchymal hamartoma of the liver in the adult: association with distinct clinical features and histologic changes. Hum Pathol 2002;33:893-8.
- Lauwers GY, Grant LD, Donnelly WH, et al. Hepatic undifferentiated (embryonal) sarcoma arising in a mesenchymal hamartoma. Am J Surg Pathol 1997;21:1248-54.
- O'Sullivan MJ, Swanson PE, Knoll J, et al. Undifferentiated embryonal sarcoma with unusual features arising within mesenchymal hamartoma of the liver: report of a case and review of the literature. Pediatr Dev Pathol 2001;4:482-9.
- Shehata B, Gupta NA, Katzenstein H, et al. Undifferentiated embryonal sarcoma of the liver is associated with mesenchymal hamartoma and multiple chromosomal abnormalities: a review of eleven cases. Pediatr Dev Pathol, in press 2010.
- Uchiyama M, Iwafuchi M, Yagi M, et al. Treatment of ruptured undifferentiated sarcoma of the liver in children: a report of two cases and review of the literature. J Hepatobiliary Pancreat Surg 2001;8:87-91.