Osteosclerotic Myeloma With Spinal Leptomeningitis and Severe Polyneuropathy

Osteosclerotic myeloma is a rare plasma cell disorder often associated with a polyneuropathy. We describe a young patient with progressive polyneuropathy associated with vertebral bone marrow lesions and unusual meningeal infiltration at cauda level. The diagnosis of osteosclerotic myeloma was confirmed by bone marrow biopsy findings including the chromosome 13q14 deletion in 37% of the cells. Leptomeningeal involvement was demonstrated by spine magnetic resonance imaging with gadolinium administration and fat-suppression technique.