Primary multicystic undifferentiated embryonal sarcoma of the liver in an adult presenting with peripheral eosinophilia

Primary undifferentiated embryonal sarcoma of liver is an extremely rare pathologic entity in the adult population. An unusual case is reported of a 44-year-old female who presented with multiple hepatic cysts and peripheral eosinophilia, initially thought to be hydatid disease of the liver. Angiogram revealed neovascularization. Surgical biopsy showed an anaplastic mesenchymal neoplasm. Pathologic findings are presented and the relevant literature reviewed. Hepatic undifferentiated embryonal sarcoma should be included in the differential diagnosis of eosinophilia accompanying hepatic cysts.