Extensive Hyperpigmented Plaques in a Chinese Singaporean Woman: A Case of Cutaneous Plasmacytosis

Cutaneous and Systemic Plasmacytosis Associated with Renal Amyloidosis

Cutaneous and systemic plasmacytosis (CSP) is a rare disorder of unknown etiology characterized by cutaneous polyclonal plasma cell infiltrates associated with various extracutaneous involvement and polyclonal hypergammaglobulinemia. Here, we report on a 54-year-old male patient with chronic renal insufficiency who presented with disseminated reddish-brown macules and plaques on the face and trunk. In our evaluation, he was found to have lymphadenopathy, polyclonal hypergammaglobulinemia; benign plasma cell infiltration involving the skin, bone marrow, and retroperitoneal area; and renal amyloidosis. To the best of our knowledge, this is the first reported case of CSP associated with renal amyloidosis.

Cutaneous and systemic plasmocytosis

Cutaneous and systemic plasmacytosis is a rare disorder observed mainly in Japanese that features an infiltration of mature plasma cells in various organ systems. In addition to the skin, lymph nodes and bone marrow are regularly affected. Laboratory tests show a polyclonal hypergammaglobulinemia. The cutaneous morphology is characterized by red to dark brown macules, papules and plaques a few centimeters in diameter, usually distributed symmetrically on the face, neck and back. Etiology and pathogenesis are not known. It is speculated that a reactive dysfunction of plasma cells may be triggered by various stimuli, such as interleukin 6. Treatment of cutaneous and systemic plasmacytosis is difficult. A standardized treatment concept does not yet exist. Topical corticosteroids and calcineurin inhibitors are mainly used.