Koichi Saito

A case of IgGλ-type solitary plasmacytoma in the maxilla associated with amyloidosis

The plasmacytoma, also called myeloma, is composed of plasma-like cells with varying degrees of differentiation. In most cases multiple lesions develop in the bone marrow, but a solitary tumor may develop in a single bone. 1-3 To establish a diagnosis of a solitary plasmacytoma it is necessary to have the following four findings: normal bone marrow except for the single affected bone, a single radiographic lesion in the bone, a biopsy of the bone lesion showing the presence of plasma cells, and no evidence of dissemination as revealed by clinical tests and radiographs made at least three years after the established diagnosis.4-6 The case presented developed in the maxillary region-a rare site to find a solitary plasmacytoma. It was also unusual because, instead of showing multiple osteolytic “punched-out” radiolucencies which is typical for this tumor, the lesion had a myxomatous-like appearance. It is known that amyloid is deposited in the oral mucosa in multiple myeloma.7-9