postrenal transplant metastatic colonic neoplasm: posttransplant lymphoproliferative disorder or adenocarcinoma?

Transplant recipients are vulnerable to a horde of infections and neoplastic conditions due to immunosuppression. Posttransplant lymphoproliferative disorder (PTLD) is a condition unique to the transplant recipient occurring due to monoclonal lymphocytic proliferation. It may affect any organ system with reportedly highest incidence in the gastrointestinal tract. The incidence of adenocarcinoma of the colon, however, has not been shown to be uniformly higher in transplant recipients. We report here an unusual case of adenocarcinoma of the ascending colon presenting with liver, lymph node and skin metastasis in a transplant recipient, which simulated PTLD both clinically and radiologically. For any gastrointestinal lesion in transplant recipient, the possibility of carcinoma must be considered. However, a high index of suspicion for PTLD facilitates early diagnosis since the treatment of the two conditions is starkly different.