Radiation recall associated with vinblastine in a patient treated for Kaposi sarcoma related to acquired immune deficiency syndrome.

A 34-year-old white man with the human immunodeficiency virus infection had a large Kaposi sarcoma lesion of his foot. This was treated with local radiation therapy consisting of 2700 rads administered in 15 fractions during a period of 28 days. Ten months later, the patient had painful disseminated Kaposi sarcoma and was treated with a 10 mg/m2 dose of intravenous vinblastine. Forty-eight hours after receiving the chemotherapy, the patient had an area of localized painful erythema develop, swelling, and vesicular eruption over the previous site of radiation therapy. This was healed by the fifth day after chemotherapy. No additional vinblastine was administered. Radiation recall occurring in a patient with significant immunosuppression (CD4 lymphocytes, 30 cells/microliters) possibly suggests that the tissue response is not a lymphocyte-mediated event.