Cutaneous and systemic plasmacytosis in a patient of Asian descent living in the United States.

Cutaneous and systemic plasmacytosis is a rare disorder characterized by widely disseminated macular skin eruptions composed of polyclonal lymphoplasmacytic infiltrates associated with variable extracutaneous involvement. Previous reports have been largely restricted to the Japanese literature. We present the first documented case of cutaneous and systemic plasmacytosis in a patient residing in the United States. This 49-year-old man, who had immigrated from Korea 19 years earlier, developed innumerable persistent pink-to-brown macular lesions over his trunk and face. Initial and repeat skin biopsy specimens revealed dense perivascular and periadnexal infiltrates of mature plasma cells, and polyclonal plasmacytosis noted on two different biopsy specimens of mildly enlarged lymph nodes. Multiple tiny pulmonary nodules were found to be of the same histologic appearance. No evidence of clonal immunoglobulin gene rearrangements or human herpesvirus type 8 infection was noted in these biopsy specimens. Treatment with antibiotics, systemic chemotherapy, and anti-CD20 antibody therapy failed to eradicate these lesions, which have persisted for 6 years. This case demonstrates that cutaneous and systemic plasmacytosis can arise in a patient of Asian ancestry, even many years after emigration to the United States.