Osteosclerotic myeloma and peripheral neuropathy.

Sixteen cases of osteosclerotic myeloma and peripheral neuropathy (SM-PN) were reviewed. The neuropathy resembled chronic inflammatory-demyelinating polyneuropathy with predominantly motor disability, high CSF protein levels, and low motor nerve conduction velocities. Twelve of the 16 patients had detectable levels of monoclonal serum proteins, all with lambda light chains, but results of other laboratory studies were usually normal. Most of the patients also had organomegaly, endocrine abnormalities, or both. Treatment of solitary lesions with tumoricidal irradiation usually improved the neuropathy and reversed the nonneurologic abnormalities; chemotherapy for multiple osteosclerotic lesions was less helpful.