1 61-year-old man had osteosclerotic myeloma that was localized in the eleventh thoracic vertebral body and associated with sensorimotor polyneuropathy, skin hyperipigmentation, edema, hypertrichosis, gynecomastia, and white nails. Cases of osteosclerotic myeloma with and without polyneuropathy in the literature were reviewed with special reference to accompanying dermatologic and endocrinologic signs and synmptoms. We assume that the polyneuropathy, cutaneous hyperpigmentation, edema, hypertrichosis, gynecomastia, and white nails are causally related to each other and are a remote effect of osteosclerotic myeloma. Quantitative histologic analysis of two sural nerves biopsied within 2 years of each other during the course of the disease indicated that both large and small myelinated fibers degenerated progressively, with relative preservation of unmyelinated fibers.