Primary cutaneous plasmacytosis

A rare acquired skin disease characterized by benign proliferation of mature plasma cells with a typical triad of cutaneous lesions, polyclonal hypergammaglobulinemia, and superficial lymphadenopathy, without an apparent underlying cause. The skin lesions consist of multiple round-to-oval, red-to-dark-brown macules, papules, and plaques most commonly found on the trunk, but also the face, neck, and axillae.