Extramedullary plasmacytoma: Cytological and genotypic studies

A 62-year-old woman had multiple plasmacytomas in the skin and lymph nodes, without Bence-Jones protein or a monoclonal peak of serum immunoglobulins. Infiltrating plasmacytoid cells expressed cytoplasmic IgG (λ) and surface CD38, without any B-cell markers. There was no visceral or bone marrow involvement suggestive of multiple myeloma. Southern blot analysis of extracted DNA from the cutaneous lesions showed two rearranged bands with an immunoglobulin, but not a T-cell receptor, gene probe. The patient showed a poor response to chemotherapy, and died of The clinical course and cytological features differentiate multiple cutaneous extramedullary plasmacytomas from solitary cutaneous extramedullary plasmacytoma and cutaneous lesions associated with multiple myeloma.