Myositis ossificans mimicking sarcoma: a not so rare bioptic diagnostic pitfall

Myositis ossificans (MO) is a heterotopic bone formation in soft tissues, usually caused by traumas or neuropathies. Although the aetiology remains unclear, MO is supposed to be an osteoblast metaplasia with a benign and self-limiting course. Remarkably, at onset MO can be clinically, radiologically and histologically indistinguishable to soft tissue malignancies, especially in cases lacking a history of trauma, leading to misdiagnoses and improper treatments.