Undifferentiated embryonal sarcoma of the liver with focal osteoid picture-a case report.

Undifferentiated embryonal sarcoma of the liver (UESL) is a rare primary liver tumor. Less than 100 adult cases were reported. It has female and right lobe preponderance. In pathological features, focal osteoid picture in UESL is never reported. We present a 63-year-old male patient with left lobe UESL with focal osteoid picture. He was admitted for a palpable solid mass, with left upper quadrant abdominal pain for 4 months. Abdominal computed tomography showed a huge well-circumscribed mass at left upper quadrant, 21.3 × 13 × 27.9 cm(3) in size, with multiple septa in delayed phase. En bloc resection including lateral segmentectomy, splenectomy, and cholecystectomy were performed, but tumor rupture was noted. The pathologic diagnosis was ruptured UESL. The postoperative course was uneventful, and adjuvant radiotherapy without chemotherapy was performed. Peritoneal seeding with massive ascites was noted in the 9(th) month after operation. Even after receiving salvage chemotherapy, he died 1 year after operation. Early complete surgical resection with adjuvant chemotherapy may improve prognosis of UESL. But the overall survival of UESL did not improve until recently. We present this case along with a literature review of the clinical pictures, diagnosis, pathology presentation, pathologicogenesis of focal osteoid picture, treatment, and prognosis for UESL of another 23 new reported cases since 2007.