Abstract
A 60-year-old female was admitted because of an abnormal shadow on chest X-ray. Computed tomography and bone scintigraphy showed a tumor of the right 8th rib. The serum gammaglobulin level was slightly high and serum M-protein was demonstrated by electrophoresis. Bone marrow biopsy of the iliac bone revealed no malignant cells. We suspected a solitary plasmacytoma of the rib and performed rib resection. The presence of monoclonality of the IgG k chain in the tumor was demonstrated by a immunohistochemical study of the operative specimen. Serum M-protein disappeared after rib resection. Solitary plasmacytoma of the rib associated with production of an M-protein at the time of diagnosis in rare. Since it is reported that about one-third of patients with solitary plasmacytoma will develop multiple myeloma, we are going to follow this patient carefully for many years, and if necessary we will add adjuvant radiotherapy.
