[Digestive Kaposi's sarcoma in patients with kidney transplantation--report of 2 cases]

Malignant tumors occur with greater frequency in patients with kidney transplants. Kaposi's sarcoma (KS), a rare vascular neoformation, represents approximately 3% of them. Its uncertain etiology appears to respond to: a chronic antigen stimulation by the transplanted tissue, to a depression of immune responsiveness, to the direct oncogenic action of the immunosuppressive agents, to the activation of oncogenic viruses or to a genetic predisposition of other possible factors. The clinical evolution is presented in two immunosuppressed kidney transplant patients with this pathology in the digestive tract. One had remission of the lesion following the suspension of the immunosuppressive agent. The relationship of this tumor with acquired immunodeficiency syndrome which occurred primarily (75%) in homosexuals shows a mortality rate of 30% due to KS. The first case showed signs of digestive hemorrhage and the typical nodule of KS was found in the esophagus on endoscopy. She also suffered a severe mixed infection due to Streptococcus faecalis and Cryptococcus neoformans with neurological complications and a new endoscopy 4 months after suspension of azathioprine showed the disappearance of the esophageal as well as the skin lesions. In the second patient, the suspicion of the digestive tract involvement could only be proved at autopsy. We insist on the importance of immunosuppression as a predisposing factor for the appearance of KS and infections in transplanted patients. It should also be remembered in cases with mucocutaneous lesions, that any digestive hemorrhage must primarily be attributed to KS and that the suspension of the immunosuppressive therapy constitutes the most effective treatment for the tumor.