Cutaneous involvement in multiple myeloma (MM): A case series with clinicopathologic correlation.

BACKGROUND: Disease-specific skin lesions are rare in patients with multiple myeloma (MM). OBJECTIVE: We sought to further characterize the clinical and pathologic features of patients with cutaneous involvement with MM. METHODS: We identified 13 patients with cutaneous lesions of MM. RESULTS: Cutaneous lesions consisted of pink, red, and violaceous papules, nodules, and/or plaques that varied in size. Histopathology revealed atypical plasma cells with occasional plasmablastic features. MM had aggressive biologic features and was at an advanced stage in the majority of patients. Despite aggressive management, including chemotherapy and stem-cell transplantation, most patients died of progressive disease within a few months after the development of cutaneous lesions. LIMITATIONS: The study group was relatively small. CONCLUSIONS: Cutaneous involvement with MM is associated with aggressive biologic behavior and short survival.