Successful treatment of post-renal transplant gastric and pulmonary Kaposi's sarcoma with conversion to rapamycin treatment.

The incidence of Kaposi's sarcoma (KS) is higher in organ transplant recipients. The lesions are mainly cutaneous and isolated visceral involvement is rare. We herewith report a 38-year-old male patient, who underwent a cadaveric donor renal transplantation for chronic interstitial nephropathy. His immunosuppression protocol consisted of corticosteroids, tacrolimus and mycophenolate mofetil. Twenty-five months later, he presented with diarrhea and epigastric pain. An upper gastrointestinal endoscopy revealed an ulcer in the body of the stomach. Histological examination coupled with immunohistochemistry was suggestive of KS. Detailed examination did not show any skin lesions. Computed tomography of the chest revealed multiple bilateral lung micronodules. The patient tested positive for anti-Herpes Human Virus (HHV8) antibodies. Tacrolimus and mycophenolate mofetil were withdrawn and rapamycin was introduced. This resulted in a regression of both stomach and pulmonary KS. One-year later, the patient developed an episode of acute rejection, which was successfully treated with bolus steroids. Our case suggests that rapamycin-based immunosuppression offers a promising approach to the management of post-transplant KS, particularly with visceral involvement.