Pleomorphic Sarcoma, Thigh

43-year-old male with chronic left thigh pain. There is an ovoid, T2-hyperintense, T1-isointense, STIR hyperintense ovoid mass arising within the proximal left vastus lateralis muscle. The lesion demonstrates well circumscribed borders and there are a few punctate regions of T1 hyperintense signal compatible with mineralization and more focal hemorrhage. A few prominent flow voids are identified within the mass itself which demonstrates heterogeneous enhancement and central necrosis. A soft tissue sarcoma was favored with the final diagnosis of pleomorphic sarcoma following biopsy. Pleomorphic sarcoma is also known as malignant fibrous histiocytoma, and formerly known as fibrosarcoma. Typical age range is between 30 and 80 years of age with a slight male predilection. Presentation is usually with a painless, enlarging, palpable soft tissue lesion. Predilection is for the retroperitoneum and proximal extremities. Treatment is with chemoradiation therapy followed by surgery. Metastatic disease is often present at the time of initial diagnosis. Prognostic factors include tumor size, location, and histologic grade.