Abstract
A 32-year-old woman visited us, complaining of a 10 cm mass on her right thigh. A biopsy specimen from the mass was consistent with undifferentiated pleomorphic sarcoma/malignant fibrous histiocytoma (UPS/MFH). Contrast-enhanced computerised tomography (CT) detected swelling of the right pelvic and inguinal lymph nodes, and positron emission tomography (PET)-CT also found integration of radio-isotope at those same lymph nodes. Histopathologically, the tumor consisted of spindle-shaped or typical round cells in a storiform pattern, with scattered bizarre tumor giant cells. Immunohistochemically, tumor cells were focally positive for E3 ubiquitin-protein ligase homolog (MDM2) and cyclindependent kinase (CDK)4. Histopathologically, the tumor was difficult to differentiate from dedifferentiated liposarcoma (DDLPS), but fluorescence in situ hybridization (FISH) showed no detection of MDM2/CEP12, hence DDLPS was deemed less likely. A diagnosis of UPS/MFH was established. Wide resection, lymphadenectomy and adjuvant radiotherapy were performed, and the patient has been free of disease for 1 year following the operation.
