Undifferentiated Sarcoma of the Liver: Clinical and Pathologic Study of 9 Cases

Moon, Kyung Chul; Kim, Chong Jai; Chi, Je G; Kang, Gyeong Hoon

Abstract

BACKGROUND: Undifferentiated sarcoma of the liver (USL) is a rare malignant tumor that is found in children and young adults.
METHODS
We performed a clinicopathologic analysis of 9 cases (M:F=4:5) of USL using immunohistochemical staining for vimentin, desmin, -smooth muscle actin (SMA), CD68, CD117, S-100, cytokeratin, epithelial membrane antigen (EMA), and p53.
RESULTS
Grossly, the tumors were large, single, and well demarcated with areas of hemorrhage and necrosis. Microscopically, the tumors were composed of spindle to stellate cells and variable numbers of multinucleated giant cells with a myxoid background. The tumors had eosinophilic globules, small cystic spaces and fibrous pseudocapsule. Under immunohistochemical study, the tumor cells were positive for vimentin, CD68 and desmin, but negative for S-100 protein. p53 overexpression was noted in most cases, and four cases showed immunoreactivity for CD117. All patients received chemotherapy before or after the excision of the tumors. Two patients died during chemotherapy, but six patients survived without recurrence for 18, 35, 53, 57, 65 and 126 months after the initial diagnosis. The remaining one patient survived with recurrence for 20 months after the initial diagnosis.
CONCLUSION
Our cases showed unique pathological and immunohistochemical features similar to the cases of previous reports. In contrast to the previous reports, the outcome of our cases were not poor. Modern multimodal treatment including surgical resection combined with multiagent chemotherapy may contribute to the better prognoses.