Answer
From question on page 192
These alarming endoscopic pictures show acute oesophageal necrosis (AEN) or so-called black oesophagus. The criteria for diagnosis include the characteristic endoscopic appearance of a diffusely black oesophagus that always ends sharply at the gastro-oesophageal mucosal junction. Ingestion of corrosive agents is excluded. AEN should be distinguished from other clinical entities, such as melanosis, pseudomelanosis, malignant melanoma, and acanthosis nigricans. AEN is confirmed histopathologically by diffuse necrosis. To our knowledge, to date only 30 cases have been reported in the literature, and the frequency was approximately 0.01% in patients undergoing upper endoscopy. AEN is often associated with deterioration of the general condition and the prognosis appears to depend mainly on the underlying illness. In this case, laboratory data revealed malnutrition and nephrotic syndrome. She was discharged, and follow up endoscopy showed an intact oesophageal mucosa three months later. When AEN is found, endoscopists should consider how to improve the patient’s general condition.