This report presents the transplantation of two kidneys and the liver from a deceased donor with suspected autoimmune encephalomeningitis (ADEM). Due to an atypical post-transplantation clinical course, the transplanted kidneys were biopsied and this disclosed diffuse large B-cell (DLBC) lymphoma of the intravascular type in each kidney. The same malignancy was found in the postmortem donor brain examination. The renal allografts from the two recipients were removed: despite every effort, one patient died, while chemotherapy was successful in the second. No malignancy was observed in the liver transplant recipient, who received prophylactic chemotherapy. These cases highlight the occasional failure of organ donor disease screening and the consequent unforeseen complications.