Acute oesophageal necrosis in multiple endocrine neoplasia type 1: an undescribed complication

Background

Acute oesophageal necrosis (AEN), also known as black oesophagus, is a rare disorder which most commonly presents as upper gastrointestinal bleeding.1–4 Other presenting symptoms include nausea, vomiting, dysphagia and epigastric abdominal pain.1 4 The pathophysiology of AEN is complex and includes multiple variables such as hypotension, which causes ischaemic injury to the oesophagus, and oesophageal mucosal injury, which can result from gastric acid.1 2 4 For example, gastric outlet obstruction causes the reflux of gastric acid reflux backwards into the oesophagus and, as such, has been implicated in cases of AEN.5 Oesophageal infections can also contribute to the development of AEN.1

Each third of the oesophagus has a unique vascular supply.2 The distal oesophagus is the most prone to ischaemic injury as its vascular supply is the least robust.2 4 The vascular supply of the stomach, in contrast, is not as vulnerable therefore the extent of mucosal necrosis does not extend distally past the gastro-oesophageal junction.4 6 Histological analysis from affected tissue demonstrates inflammation and necrosis, with the depth of necrosis proportional to the degree of injury.6

There are multiple known risk factors for the development of AEN including male sex, elderly age and certain chronic medical conditions such as diabetes mellitus, malnutrition, renal insufficiency and malignancy.1 2 4 Here we present an atypical and severe case of acute oesophageal necrosis in a patient with multiple endocrine neoplasia type 1 (MEN1), which is a rare presentation of Zollinger-Ellison syndrome (ZES).

Case presentation

A 56-year-old man with MEN1, complicated by hyperparathyroidism and multiple pancreatic neuroendocrine tumours, and gastro-oesophageal reflux disease (GORD) on chronic proton pump inhibitor (PPI) therapy presented for an elective right lower lobectomy and thymectomy for lung and presumed thymic neuroendocrine tumours (NETs). His home medications were omeprazole 40 mg once daily and vitamin D 4000 IU once daily. He had multiple family members with MEN1 including a maternal aunt with ZES. He denied any tobacco use and denied regular heavy alcohol use.

The operation was uncomplicated however he experienced significantly postoperative pain. His pain management regimen included regularly scheduled intravenous ketorolac. On postoperative day 5, he began to report progressively worsening nausea and GORD. These symptoms were so severe that they interfered with his sleep. The following day, his symptoms progressed to include abdominal pain and distention. He then developed new-onset atrial fibrillation with hypotension.

Laboratory examination demonstrated a haemoglobin decline from 9.4 g/dL earlier that morning to 6.2 g/dL. Creatinine was 1.21 mg/dL and blood urea nitrogen was elevated at 62 mg/dL. Liver function panel was within normal limits. Lactate was elevated at 2.3 mmol/L.

He denied any overt bleeding including no vomiting, melena or haematochezia. He was transferred to the intensive care unit (ICU). In the ICU, a nasogastric tube was placed which put out 700 mL of dark red blood; after this, he reported that his abdominal distention and pain were mildly improved. He was given 3 L of normal saline and intravenous PPI therapy (80 mg intravenous bolus of pantoprazole followed by 8 mg/hour continuous infusion) as well as transfused packed red blood cells. Gastroenterology was consulted emergently.

On our exam, the patient was still in significant distress due to abdominal pain. He was febrile at 101.3 °F, tachycardic with heart rate in the 130s and with persistently low-normal blood pressures despite volume resuscitation. His abdomen was distended and tender but without rebound.

Investigations

An emergent upper endoscopy was performed at bedside which demonstrated circumferential black oesophageal mucosa extending proximally from the gastro-oesophageal junction (figure 1), consistent with acute oesophageal necrosis. His gastric mucosa was noted to appear pale. An adherent obstructing clot in the duodenal bulb (figure 2) was not able to be traversed (Forrest score classification IIB), conferring the patient a Rockall score of 7 (associated with 43.8% risk of rebleeding and 27% mortality).

Differential diagnosis

The differential diagnosis of the patient’s acute oesophageal necrosis included hypotension-induced ischaemia (caused by blood loss from the duodenal ulcer, atrial fibrillation and/or arterial occlusion), gastric acid reflux into the oesophagus and/or a postoperative oesophageal infection given his recent thoracic surgery.

Treatment

A CT-angiogram of the abdomen/pelvis was performed which showed patent abdominal vasculature and a few small pockets of free air, which was concerning for a perforated ulcer. Given the phase timing used for this contrast study to identify vessel patency, it was inadequate to visualise known pancreatic lesions. The patient stabilised with conservative therapy consisting of nil-per-os (NPO) diet restriction and continuous intravenous PPI therapy. He was also given prophylactic antimicrobial therapy with meropenem and micafungin. Due to differing medical opinions, the decision was made to repeat the endoscopy in order to re-assess the duodenal ulcer and plan for definitive treatment if necessary.

Outcome and follow-up

A repeat upper endoscopy 36 hours later, performed in the operating room given the high risks of the procedure, demonstrated healing oesophageal mucosa with exudates (figure 3) and normal gastric mucosa. The duodenal clot was able to be traversed during this endoscopy and the second portion of the duodenum was able to be examined, however it was found to contain extensive necrotic mucosa. Due to this finding, the patient was taken for emergency exploratory laparotomy which confirmed the presence of duodenal necrosis as well as revealed a perforated duodenal ulcer (figure 4) eroding into the gastroduodenal artery. A pancreaticoduodenectomy was performed given areas of the duodenum were ischaemic and necrosed beyond primary repair. On pathological examination, the duodenum contained microscopic foci of neuroendocrine tumour consistent with gastrinoma. Fortunately, the patient recovered and was able to be discharged home.