Colonic lymphoma as a cause of massive rectal bleeding in a cardiac transplant recipient.

Lower gastrointestinal hemorrhage in immunosuppressed transplant recipients is associated with significant morbidity and mortality. This hemorrhage is often massive and frequently due to ulceration of the colon by opportunistic organisms requiring early diagnosis and resection. We report a heart transplant recipient with massive rectal bleeding from an unsuspected lymphoproliferative lesion of the sigmoid colon treated successfully with prompt surgical resection and reduction of immunosuppression. Although lymphoproliferative lesions are common in transplant recipients, particularly in those immunosuppressed with cyclosporine, we believe massive rectal bleeding to be a unique presentation of such a lesion.