Parosteal osteogenic sarcoma of the hand.

Osteosarcomas of the tubular bones of the hands and feet are rare tumours and the initial biopsies are frequently misdiagnosed. We report a case of parosteal osteosarcoma arising in the metacarpal of a female patient aged 53 at first presentation. The tumour recurred three times over two decades and eventually metastasized to the lungs. The differential diagnosis includes florid reactive mesenchymal proliferation and bizarre parosteal osteochondromatous proliferations of the tubular bones of the hand.