[Multiple myeloma presenting as a solitary tumor of the rib; report of a case].

A 78-year-old man complained of right lateral chest pain. Chest X-ray showed an abnormal shadow in the right upper lung field and chest computed tomography (CT) scan showed a lateral chest wall tumor sorrouding the right 4th rib. Bone scintigraphy revealed only one lesion in the right 4th rib. Chest wall tumor resection was done. Histological analysis of the tumor specimen showed plasmacytoma. After the operation, the diagnosis of multiple myeloma was established by demonstration of myeloma by a bone marrow biopsy. Multiple myeloma should be taken into account as one of causes of a chest wall tumor even if it is a solitary tumor of the rib.