Nivolumab-induced immune-mediated acute gastritis in a melanoma patient

Immune-mediated acute gastritis (IMAG) is a rare side effect of nivolumab therapy. A 49-year-old patient with metastatic melanoma developed IMAG during nivolumab treatment. In the 5th month of treatment, the patient complained of epigastric pain, nausea, vomiting, loss of appetite, and weight loss. Esophagogastroduodenoscopy and biopsy were performed, and the diagnosis of IMAG was pathologically confirmed. In addition to the discontinuation of nivolumab treatment, proton pump inhibitor and corticosteroid treatment were administered, and the complaints of the patient disappeared after 1 week. Since nivolumab is frequently used in melanoma patients, IMAG should be considered and diagnostic procedures should be performed in patients with symptoms suggestive of acute gastritis during treatment, although it rarely develops.