Acute esophageal necrosis (AEN), also known as “black esophagus” or Gurvits syndrome, is a rare but serious condition which was first described by Goldenberg et al. [1] in 1990. The incidence is reported ranging from 0.01% to 0.28% [2]. It is characterized by a striking black discoloration of the esophageal mucosa due to tissue necrosis. The pathogenesis of AEN is considered multifactorial, with contributing factors including ischemia, mucosal injury, and impaired mucosal defense mechanisms. Risk factors for AEN include advanced age, male gender, and chronic conditions such as hypertension, diabetes mellitus, renal insufficiency, liver disease, malnutrition, and excessive alcohol use [3]. Clinical presentations commonly include upper gastrointestinal bleeding, chest or abdominal pain, nausea and vomiting, dysphagia or dyspnea.

Here we report a case of AEN diagnosed in previously undiagnosed diabetes mellitus patient who visited emergency room complaining dyspnea.

A 70-year-old Korean man presented to the emergency department with progressive dyspnea. The patient initially presented with dyspepsia and mild vomiting without hematemesis or melena, which began three days prior and progressively evolved into dysphagia and odynophagia. On the day of presentation, he reported worsening dyspnea. He denied any significant past medical history. At emergency room, his body temperature was 36.3°C, blood pressure was measured as 145/84 mm Hg, heart rate was 140 beats/min, and respiratory rate was 32 breaths/min. Laboratory findings revealed hemoglobin of 12.9 g/dL, white blood cell count of 28400/μL (neutrophils 91.9%), platelet count of 207000/μL, high anion gap metabolic acidosis with respiratory compensation (arterial pH 7.401, pCO2 14.9 mm Hg, bicarbonate 9.3 mmol/L), severe electrolyte imbalances (sodium 117 mmol/L, potassium 3.0 mmol/L, chloride 67 mmol/L), hyperglycemia (252 mg/dL), and elevated serum ketones (4.9 mmol/L; normal level ≤0.6 mmol/L).

Chest computed tomography revealed diffuse esophageal wall thickening without cardiac or pulmonary abnormalities. Esophagogastroduodenoscopy (EGD) revealed diffuse black discoloration of the entire esophagus. In contrast, the gastric mucosa was normal in color with a clearly demarcated boundary at the esophagogastric junction. The duodenum also exhibited normal mucosal appearance (Fig. 1).

Biopsy of the esophageal mucosa showed diffuse fibrinoid and suppurative necrosis with numerous filamentous fungal hyphae (Fig. 2). This patient was diagnosed with AEN combined with esophageal candidiasis. His AEN seemed to be triggered by diabetic ketoacidosis secondary to previously undiagnosed diabetes mellitus, as indicated by an elevated HbA1c of 11.7%.

The patient was treated with fluid resuscitation, intravenous proton-pump inhibitors (PPIs), insulin therapy, bicarbonate infusion, electrolyte replacement, bowel rest with parenteral nutritional support. His esophageal candidiasis was treated with fluconazole for 14 days. The patient showed favorable recovery, and oral intake was permitted on day 5 of hospitalization. He was discharged on hospital day 15. After discharge, he remained on oral PPI therapy to maintain a less corrosive environment in the esophagus, completing a total of two months of treatment. A follow-up EGD performed at three months demonstrated complete mucosal healing without sequelae (Fig. 3).

AEN typically presents in elderly males with symptoms of upper gastrointestinal bleeding. Other presenting symptoms may include dysphagia, chest pain or abdominal pain. Although this patient initially experienced mild dysphagia, dyspnea was the chief complaint upon presentation to the emergency department.

Etiology of AEN is multi-factorial and usually results from combination of esophageal ischemia, impaired mucosal barrier protection, and reflux of gastric contents. Other risk factors included diabetes mellitus, hematologic and solid organ malignancies, malnutrition, gastric outlet obstruction, renal insufficiency, hemodynamic compromise and shock; the underlying pathogenesis was related to poor perfusion and nutritional states. As we can notice in this case, diabetic ketoacidosis is recognized as one of its causes, and AEN is attributed to ischemic damage to the lower esophagus, a watershed area, resulting from fluid loss from osmotic diuresis and worsened by diabetes-related atherosclerosis [4]. AEN in post-operative period or post endoscopic retrograde cholangiopancreatography were also reported [5,6].

EGD is usually the gold standard for diagnosis of AEN, which typically reveals diffuse circumferential black esophageal mucosa starting at the gastroesophageal junction and extending proximally. A sharp transition is observed at the gastroesophageal junction, where the mucosa resumes its normal pink appearance. The differential diagnosis includes malignant melanoma, acanthosis nigricans, esophageal melanocytosis, pseudomelanosis, and coal dust pigmentation [2].

Treatment of AEN primarily focuses on supportive care and management of underlying conditions. Medical management of AEN includes aggressive hydration and intravenous PPI therapy. Antimicrobial treatment is warranted in the presence of microbiological or histopathological evidence of infection, such as positive esophageal cultures, identification of fungal organisms on stains, or histologic detection of multinucleated giant cells or inclusion bodies. This patient was empirically given antibiotics (meropenem) from the emergency room and maintained for a week and later treated for esophageal candidiasis which was diagnosed with esophageal biopsy specimen. Nasogastric tubes insertion should be avoided because it can increase the risk of esophageal perforation [3].

AEN carries a high mortality rate, ranging from 30% to 50%. Complications include esophageal stricture or stenosis, perforation with mediastinal infection or abscess formation, superinfection, and death. A systematic review of 319 cases reported that 21.9% of patients developed serious complications such as sepsis or esophageal perforation [7]. According to that study, patients with pain or ketoacidosis tend to have a better prognosis after AEN. As described above, the patient initially denied any relevant medical history, and the diagnosis of diabetic ketoacidosis with concomitant AEN was not made immediately. However, he responded well to treatment and recovered without sequelae. Early recognition and prompt hemodynamic stabilization through aggressive resuscitation are key principles in the management of AEN, contributing to improved clinical outcomes [8,9].

In conclusion, AEN is a rare clinical syndrome associated with esophageal ischemia secondary to various serious underlying conditions. Given its potential for life-threatening complications, early detection is crucial, especially among elderly patients with multiple comorbidities, and should be followed by prompt and appropriate intervention to reduce severe morbidity and mortality.