Severe Gastritis Due to Nivolumab Treatment of a Metastatic Melanoma Patient.

Nivolumab, an anti-PD-1 check point inhibitor, is an immunotherapeutic agent, representing a major step in the treatment of melanoma. However, its use is associated with severe toxicities. Among them, gastrointestinal (GI) disorders from the lower GI tract have been widely reported. On the contrary, disorders from the upper GI tract are rare. Such a case of delayed nivolumab induced severe gastritis in a 53-year-old Caucasian female patient suffering metastatic melanoma is described. The patient's symptoms from the upper GI tract began 4 months after nivolumab treatment initiation. The diagnosis was based on imaging, including PET/CT, endoscopical and pathological findings. The side effect was successfully treated with prolonged administration of proton pump inhibitors and corticosteroids. There are only a few cases of immune check point inhibitors (ICPis) induced upper GI tract disorders, while it seems that the symptoms from nivolumab induced upper GI tract damages appear later than those reported in the lower part. Nivolumab, among other side effects, may cause severe gastritis. Hence, this pathological entity should be included in the list of this drug's side effects.