Dermatopathology of skin cancer in solid organ transplant recipients

Skin cancers occur more frequently in solid organ transplant recipients relative to the general population. Transplant recipients are at particularly high risk of squamous cell carcinoma, with up to a 100-fold increase in the relative risk when compared to the nontransplanted population. This compares with a 10- to 16-fold increase in basal cell carcinoma for renal transplant recipients. An increased incidence of melanoma in transplant patients has also been reported. Other types of skin cancer associated with immunosuppression in transplant patients include Kaposi sarcoma, Merkel cell carcinoma, and posttransplant lymphoproliferative disorder. This review discusses the epidemiology and pertinent pathologic features of each of these tumors. A brief clinical management strategy is outlined. In addition, the contribution of viral induced carcinogenesis with respect to Kaposi sarcoma, Merkel cell carcinoma, and posttransplant lymphoproliferative disorder is discussed.