A 73-year-old male with a history of chronic obstructive pulmonary disease and stage IV lung adenocarcinoma, being treated with the PD-1 inhibitor nivolumab, presented to the Emergency Room with a two-day history of coffee ground emesis and melena. On examination, he was tachycardic (130 per minute) and hypotensive (95/55 mmHg). Laboratory studies revealed anemia (6.9 g/dl), leukocytosis and hyper-lactatemia (lactate 6.3 mmol/l). Esophagogastroduodenoscopy was performed which showed diffuse circumferential blackish, necrotic-appearing mucosa of the first third of the esophagus. These findings were consistent with a diagnosis of acute esophageal necrosis (AEN). A biopsy of the esophageal mucosa demonstrated fragments of necrotic tissue with predominant lymphocyte infiltration. He was managed with a strict restriction of oral intake, total parenteral nutrition, double-dose proton pump inhibitors and broad-spectrum antibiotics (piperacillin/tazobactam). Despite the measures adopted, the patient presented a progressive clinical deterioration and died of multiple organ failure 12 days after admission.