Neoplastic consequences of transplantation and chemotherapy.

An increased incidence of certain neoplasms occurs in immunodeficiency states. The incidence of cancer in organ transplant patients is approximately 4%. The predominant tumors are lymphomas, carcinomas of the skin and lips, carcinomas of the vulva/perineum, in situ carcinomas of the uterine cervix, and Kaposi sarcoma (KS). Tumors appear a relatively short time after transplantation. Unusual features of the lymphomas are the high incidence of non-Hodgkin lymphomas, frequent involvement of extranodal sites, and marked predilection for the brain. Skin cancers present unusual features: predominance of squamous cell carcinomas, young age of the patients, and a high incidence of multiple tumors. Cancers of the vulva/perineum occur at a younger age than in the general population and may be preceded by condyloma acuminatum or herpes genitalis. Lymphomas, leukemias, and skin cancers are increased in nontransplant patients who receive immunosuppressive therapy for nonmalignant diseases. Second tumors that develop in cancer patients, after treatment with cytotoxic therapy, are mainly leukemias, lymphomas, and bladder carcinomas.