[A case of polyneuropathy associated with osteosclerotic myeloma]

A 50-year-old woman presented with sensorimotor polyneuropathy in the lower limbs. Biopsy of the muscle revealed neurogenic changes, and electrophysiological study and pathology of the biopsied nerve indicated myelinoaxonal degeneration. Her symptoms responded to neither plasmapheresis nor prednisolone. Pelvic radiography disclosed an osteosclerotic lesion that was subsequently diagnosed as IgA-lambda plasmacytoma by biopsy. Radiation therapy for this solitary osteosclerotic myeloma improved the patient's polyneuropathy. In Japan, reports of cases of polyneuropathy associated with osteosclerotic myeloma without multiorgan disorders as in our case have not previously been described; thus, such cases may be misdiagnosed. Therefore, in patients with polyneuropathy of unknown etiology, a systemic bone survey and repeated searches for M-protein are important. Treatment of bone lesions in patients with solitary osteosclerotic myeloma may improve the associated polyneuropathy.