ABSTRACT
A 46-year-old male patient developed scatterred reddish-brown plaques and nodules on the back 6 years prior to the presentation. Then, the lesions gradually spread to the axillary fossa and protothorax, and became indurated with slight itching in winter. Laboratory examination revealed hypergammaglobulinemia. Computed tomography(CT)scan showed multiple nodular or patchy shadows in both lungs, lymphadenectasis in axillary, mediastinal and inguinal regions, and spleen enlargement. Histopathological examination of skin lesions showed granulomatous infiltrates with plenty of lymphocytes, histiocytes and mature plasma cells in the middle and lower dermis with the presence of lymphoid follicle-like structures, but no cell atypia was observed. Immunohistochemical study showed positive staining for CD38, CD138, CD79a, κ and λ light chains. According to clinical manifestations and laboratory examination results, the patient was diagnosed with cutaneous and systemic plasmacytosis.