Osseous metaplasia associated with amyloid-producing plasmacytoma of bone: a report of two cases.

Amyloid-producing plasmacytoma of bone is a rare myeloma variant. We describe two patients with plasmacytomas of bone with extensive amyloid deposition and metaplastic bone formation which can be confused on imaging with osteosarcoma. Histologic confirmation was obtained in both cases. Metaplastic new bone formation was identified within these lesions and appears to be responsible for the radiographic appearances.