Clinicopathologic Features and Diagnostic Challenges of Mycophenolate Mofetil-Associated Enterocolitis in Lung Transplant Recipients.

Mycophenolate mofetil (MMF) is a commonly used immunosuppressant for lung transplant recipients. Although it efficiently suppresses transplant rejection and improves graft function, MMF has been found to occasionally cause gastrointestinal (GI) injury. The symptoms are nonspecific and include diarrhea, nausea, vomiting, and rare cases of bleeding. Endoscopic findings range from normal appearance to erythema to ulcers. The histopathologic features mimic several different disorders like graft-versus-host disease (GVHD), cytomegalovirus (CMV) colitis, ischemic colitis, or inflammatory bowel disease (IBD). The nonspecific symptoms, unremarkable endoscopic findings, and overlapping pathological features make the accurate diagnosis of MMF-associated enterocolitis (MAE) very challenging. There are limited case reports regarding MAE in lung transplant patients; however, systematic studies are lacking. Therefore, we analyzed clinical, endoscopic, and pathological features in 12 lung transplant recipients with MAE and aim to improve the recognition of diagnostic challenges.