Primary cutaneous giant cell plasmacytoma in an organ transplant recipient: a rare presentation of a posttransplant lymphoproliferative disorder.

Posttransplant lymphoproliferative disorder (PTLD) is comprised of a spectrum of lymphoid diseases, ranging from early lesions, such as plasmacytic hyperplasia, to monomorphic neoplasms, including plasmacytoma-like lesions. Although PTLD may involve a variety of organs, primary cutaneous PTLD is rare. We report a unique case of Epstein-Barr virus (EBV)-positive primary cutaneous giant cell plasmacytoma developed 5 years after renal/pancreatic transplant in a 55-year-old male patient. The patient received local radiotherapy without reduction in immunosuppression and responded well. A review of the literature identified additional 49 cases of primary cutaneous B-cell PTLD, including 18 cases of plasmacytoma-like lesions. Primary cutaneous B-cell PTLD usually presents years after transplantation, has male preponderance, tends to occur on extremities, is frequently EBV-associated, and predicts a favorable clinical outcome. Unlike PTLD in general, in which EBV-positive cases usually occur earlier than EBV-negative ones, the longer presentation interval in the cutaneous PTLD seems to be uncorrelated to EBV status. Compared with other subtypes of cutaneous B-cell PTLD, plasmacytoma-like lesions have an increased male preponderance and tendency to present on the extremities. Although the majority of cases have been treated with reduction of immunosuppression, antiviral therapy and/or local radiotherapy, and a few with chemotherapy, the best therapeutic intervention for primary cutaneous B-cell PTLD remains to be further investigated with the analysis of more reported cases and large clinical trials.