Undifferentiated ( Embryonal ) Sarcoma of the Liver: A case report including immunohistochemical, electronmicroscopic and flow-cytometric study

ABSTRACT

Undifferentiated(embryonal) sarcoma of the liver developing predominantly in the late childhood is extremely rare in malignant hepatic tumors. It has been described by a variety of terms such as malignant mesenchymoma, embryonal sarcoma, fibromyxosarcoma, embryonal rhabdomyosarcoma or primary sarcoma of the liver. The tumor usually presents a huge mass containing solid and sometimes cystic components, and is cmposed of large stellate and spindle cells in an abundant myxoid matrix. The treatment of choice is surgical resection with or without adjuvant chemotherapy and/or radiotherapy, but the prognosis of this disease has been reported extremly poor. We experienced a case of undifferentiated(embryonal) sarcoma of the liver recently which was confirmed by pathological examinations in a 18-year-old boy. He visited our hospital for examination of the progressive growing RUQ abdominal mass detected incidentally. On physical examination, a firm, non-tender, hard, fixed, huge, abdominal mass was palpated in the right upper quadrant of abdomen. Abdominal ultrasonography, computerized tomography and magnetic resonance imaging showed a 10x15cm sized mass confined to the left lobe of the liver, and it was hypovascular mass on angiography. We performed left lobectomy including the tumor and it was confirmed as undifferentiated (embryonal) sarcoma of the liver by pathologic examination. We herein report this case including histologic, electronmicroscopic and flow cytometric results with the review of literatures.