[Undifferentiated (embryonal) liver sarcoma: reviaew of 6 cases in National Cancer Institute, Lima, Peru. Review of the literature].

Undifferentiated (embryonal) liver sarcoma is a rare tumor about 2% of all malignant liver tumors with a poor prognosis and usually occurs in children, this review aims to assess cases of primary embryonal sarcoma of the liver presented at our institution the past 8 years and improve recognition of its variants and evaluate immunohistochemical characteristics that help differentiated it from other tumors. Six cases of undifferentiated liver sarcoma were histologically evaluated and investigated by immunohistochemistry with a panel of antibodies using the equipment “Autostainer Link 48”. Usually masses were on average more than 20 cm, with solid, cystic, mucinous areas. The microscopic features include cells of spindle cell appearance, oval, starry, epithelioid and multinucleated cells densely arranged in a myxoid matrix. Trapped bile ducts and hepatic cords often present in the periphery of tumors. Intracellular and extracellular PAS positive hyaline globules. Immunohistochemistry showed very divergent differentiation.