Perforating Colitis Secondary to Immune Checkpoint Inhibitor Use in a Patient With Pericolonic Involvement by Rosai-Dorfman Disease

Recently, the use of immunotherapy has increased substantially for the treatment of several malignancies. It is associated with several gastrointestinal adverse events; however, severe complications such as intestinal perforation are rare. We present a 75-year-old man with metastatic melanoma, presented with profuse diarrhea and abdominal pain, after ipilimumab and nivolumab administration. Shortly after, he developed fulminant colitis and intestinal perforation and was found to have concurrent Rosai-Dorfman disease of pericolonic lymph nodes. With the increasing use of immunotherapy, reporting of serious adverse events and their mimics is essential. In addition, further studies are required to investigate whether an association exists between Rosai-Dorfman disease and immunotherapy.