Recurrent Kaposi's sarcoma in a renal transplant recipient: Regression following treatment of cytomegaloviremia with ganciclovir

Kaposi's sarcoma is a rare tumor occurring with a particularly high frequency in immunosuppressed patients with transplants or the acquired immune deficiency syndrome. There is considerable evidence associating cytomegalovirus (CMV) infection with the occurrence of Kaposi's sarcoma (KS), including the demonstration in hybridization experiments of CMV DNA and RNA in KS. We report an HIV-negative renal transplant recipient, with a history of KS 20 years previously that was treated successfully with radiation therapy. Nine months following kidney transplantation, the KS recurred and progressed despite marked reduction of immunosuppression. He was treated with ganciclovir after the demonstration of 1) CMV and CMV DNA in blood cultures, and 2) CMV DNA in specimens of KS, but not in normal contiguous skin. The KS lesions subsequently halted, most regressed, and his viremia cleared. The lesions may have regressed spontaneously or secondarily to reduction in immunosuppression. A third more intriguing possibility is that regression of the recurrent KS may have been related to treatment of the CMV-viremia. If so, this represents further evidence associating CMV with KS. Mechanisms may involve the eradication of CMV as an immunosuppressive agent, infectious agent, and/or oncogene, with subsequent immune enhancement.