the patient lost to follow up after initial sonographic and radiographic evaluation and 6 months later, presented with worsening symptoms. He underwent an MRI of the right thigh followed by a biopsy

histopathology: High grade undifferentiated pleomorphic sarcoma (previously known as malignant fibrous histiocytoma). Immunohistochemically, tumor cells react positively for Vimentin (V9) while negatively for Desmin (D33), SMA (1A4), Myo-D1 (5.8), S100 (polyclonal), CD34 (Qbend10), SOX10 (EP268), and PAN CK (AE1/AE3)