The present study reports a case of cutaneous plasmacytosis in a 51-year-old patient suffering from infiltrated erythema of the right lower lateral femur for 4-5 years and perioral and abdominal erythema for 1 year. Histopathological examination showed that dense mature plasma cell-dominant inflammatory cell infiltration appeared in the deep dermis and between part of the subcutaneous tissues and that there were small numbers of lymphocytes and polykaryocytes. Immunopathogenetic analysis showed that the infiltrating plasma cells were positive for CD79a and CD138. The patient was diagnosed with cutaneous plasmacytosis.
Keywords: cutaneous plasmacytosis.