Abstract: Cutaneous plasmacytosis (CP) is a rare skin disorder characterized by multiple reddish brown nodules with polyclonal plasma cell proliferation. We report three patients with cutaneous plasmacytosis. Two patients had infiltrating dark red plaques on the lower limbs, one patient presented with red patches on the scalp which was clinically rare. γ-globulin level elevated in two patients, IL-6 level elevated in one patient, three patients had abnormal urine protein electrophoresis. Histopathology showed that there were many plasma cells infiltrating in the dermis, and Kappa and Lambda were positive in immunohistochemistry. All three patients were treated with methotrexate and improved.

Key words: plasmacytosis, cutaneous