Multicentric plasma cell variant of Castleman's disease with cutaneous involvement.

BACKGROUND: Castleman's disease (CD) is a rare low-grade B-cell lymphoproliferative disorder that can be associated with a variety of antibody-mediated paraneoplastic syndromes. The disease is classified clinically by two forms and three histologic variants. METHODS: We describe the clinical and pathological features of a 44-year-old woman who presented with an autoimmune hemolytic anemia, thrombocytosis, polyclonal gammopathy, axillary lymphadenopathy, hepatosplenomegaly, and several erythematous and violaceous nodules and plaques without scaling involving the trunk and extremities. RESULTS: Histologic examination of the skin lesions revealed a deep dermal and subcutaneous nodular mononuclear infiltrate composed primarily of polyclonal plasmacytoid cells without atypia and an increased vascular proliferation. Additional studies including a bone marrow and lymph node biopsy, serum and urine protein electrophoresis, and computed tomography scans supported the diagnosis of multicentric plasma cell variant of CD with an associated autoimmune paraneoplastic hemolytic anemia. CONCLUSION: Cutaneous involvement in CD is part of the multicentric nature and should be considered in the differential diagnosis of a polyclonal plasma cell-rich lymphoproliferative disorder associated with paraneoplastic autoimmune disease.