Fasciitis ossificans with a radial neuropathy: a benign differential diagnosis for soft tissue sarcoma.

A soft tissue mass with an associated neuropathy suggests a malignancy with nerve compression or infiltration. However, there are benign diagnoses to consider. We report a case of an axillary mass with a radial nerve neuropathy, initially suspected to be a soft tissue sarcoma. The final diagnosis was fasciitis ossificans. This is the first such reported case. The presence of severe pain and tenderness suggested an inflammatory process. Fasciitis ossificans is a rare form of heterotopic bone formation, commonly presenting with signs of local inflammation or pain.