Multicentric Castleman disease with cutaneous manifestations: report of 2 cases and comparison with systemic plasmacytosis.

We report 2 patients with multicentric Castleman disease. Both presented with multiple, indurated, hyperpigmented plaques, generalized lymphadenopathy and polyclonal hypergammaglobulinemia. Biopsy specimens showed infiltration of mature plasma cells and lymphocytes in the dermis and lymph nodes. Skin specimens were negative for human herpesvirus 8, latent nuclear antigen 1 and Epstein-Barr virus by in situ hybridization. PCR disclosed clonal T-cell receptor gene rearrangement in the bone marrow cells of 1 patient. We discuss the possible relationship between multicentric Castleman disease and systemic plasmacytosis as well as plasma cell proliferation.