Video Endoscopic Sequence 1 of 7.

The Black Esophagus: Acute Esophageal Necrosis Syndrome

A 70 – year old man, with cholangiocarcinoma was admitted to our ward because septicemia and medically compromised patient.

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Video Endoscopic Sequence 2 of 7.

The "black esophagus" is an extremely rare endoscopic finding.

Acute esophageal necrosis (AEN), commonly referred to as “black esophagus”, is a rare clinical entity arising from a combination of ischemic insult seen in hemodynamic compromise and low-flow states, corrosive injury from gastric contents in the setting of esophago-gastroparesis and gastric outlet obstruction, and decreased function of mucosal barrier systems and reparative mechanisms present in malnourished and debilitated physical states. AEN may arise in the setting of multiorgan dysfunction, hypoperfusion, vasculopathy, sepsis, diabetic ketoacidosis, alcohol intoxication, gastric volvulus, traumatic transection of the thoracic aorta, thromboembolic phenomena, and malignancy.

A typical patient with AEN is an elderly male with multiple medical comorbidities, who manifests with signs of upper gastrointestinal bleeding. Clinical presentation of AEN ranges from hematemesis, coffee ground emesis, and melena (overall, accounting for nearly 90% of the cases) to asymptomatic black esophagus that was noted during a percutaneous gastrostomy tube placement Generally, uncomplicated AEN follows an indolent clinical course and has a predictable endoscopic and histopathological trajectory.

Video Endoscopic Sequence 3 of 7.

Endoscopy of The Black Esophagus

Clinical presentation is remarkable for upper gastrointestinal bleeding. Notable symptoms may include epigastric/abdominal pain, vomiting, dysphagia, fever, nausea, and syncope. Associated laboratory findings may reflect anemia and leukocytosis. The hallmark of this syndrome is the development of diffuse circumferential black mucosal discoloration in the distal esophagus that may extend proximally to involve variable length of the organ. Classic “black esophagus” abruptly stops at the gastroesophageal junction. Biopsy is recommended but not required for the diagnosis. Histologically, necrotic debris, absence of viable squamous epithelium, and necrosis of esophageal mucosa, with possible involvement of submucosa and muscularis propria, are present. Classification of the disease spectrum is best described by a staging system.

Video Endoscopic Sequence 4 of 7.

Endoscopy of The Acute Esophageal Necrosis Syndrome

Treatment is directed at correcting coexisting clinical conditions, restoring hemodynamic stability, nil-per-os restriction, supportive red blood cell transfusion, and intravenous acid suppression with proton pump inhibitors. Complications include perforation with mediastinal infection/abscess, esophageal stricture and stenosis, superinfection, and death. A high mortality of 32% seen in the setting of AEN syndrome is usually related to the underlying medical co-morbidities and diseases.

Video Endoscopic Sequence 5 of 7.

Endoscopy of The Black Esophagus

Proximal esophageal extension is common. Biopsy is recommended although not required to make the diagnosis. First described in 1990 by Goldenberg et al

Male sex, older age, chronic medical conditions, including diabetes mellitus, hematologic and solid organ malignancy, malnutrition, renal insufficiency, cardiovascular compromise, trauma, and thromboembolic phenomena place a patient at a higher risk for developing AEN. Clinical presentation is almost universally related to upper gastrointestinal bleeding. Complications may include stenosis or stricture formation in the distal esophagus, perforation, mediastinitis, and death. Overall mortality is largely related to the underlying medical condition and approaches 32%.

Video Endoscopic Sequence 6 of 7.

Biliary Plastic Stent

Our patient has the diagnosis of a cholangiocarcinoma

Classic AEN presents as a circumferential, black-appearing, diffusely necrotic esophageal mucosa, preferentially affecting the distal esophagus, of variable length, that stops abruptly at the GEJ. Proximal extension of the mucosal injury is common and the entire esophagus can appear black. Differential diagnosis includes malignant melanoma, acanthosis nigricans, coal dust deposition, pseudomelanosis, and melanocytosis of the esophagus. Detailed history and physical examination provide essential clues to the diagnosis. Classic endoscopic appearance may be supported by brush cytology or biopsy specimen that will confirm the diagnosis. This is especially important in rare cases of isolated involvement of proximal and middle esophagus. Additionally, a history of corrosive ingestion should be sought for and diligently excluded.

Differential diagnosis — The differential diagnosis includes several conditions in which the esophageal mucosa may also appear darkened or in which other gross findings can be similar.

Melanosis — Esophageal melanosis has been described in patients with underlying chronic esophagitis. It is most commonly seen in the distal esophagus.

Pseudomelanosis — Pseudomelanosis is due to tissue deposition of pseudomelanin, a "wear and tear" pigment derived from lysosomal degradation. Histologically it is seen as brown pigment within macrophages.

Melanoma — Melanoma of the esophagus is rare. It usually originates in the mid and lower esophagus.

Acanthosis nigricans — Acanthosis nigricans is characterized by velvety, verrucous, hyperpigmented skin and mucosal plaques. While it can be benign, it can also be a paraneoplastic phenomenon, commonly associated with intra-abdominal malignancies.

Coal dust and exogenous dye ingestion — Coal dust or carbon is the most common exogenous pigment to deposit in human body tissues. The mechanism by which coal dust is deposited in the esophagus is unclear.

Pseudomembranous esophagitis — Pseudomembranous esophagitis has generally been reported in association with serious systemic illness. A thin, yellow or black, concentric membrane coats the distal (and less commonly entire) esophagus. The membrane can be dislodged revealing a friable underlying mucosa . Some cases may represent a variant of acute esophageal necrosis.

Video Endoscopic Sequence 7 of 7.

Classic AEN presents as a circumferential, black-appearing, diffusely necrotic esophageal mucosa, prefeCholangiocarcinoma is a slow-growing malignancy of the bile duct. It is the second most common primary hepatic tumor after hepatoma. The cause of bile duct cancer is unclear. Results of some epidemiologic studies have implicated bacteria-induced carcinogens derived from bile salts (eg, lithocholate) as a causative factor in the pathogenesis of cholangiocarcinomas. Biliary ductal calculi occur in 20-50% of patients with cholangiocarcinoma; however, the association of gallstones with cholangiocarcinoma is less marked than it is with carcinoma of the gallbladder. The most common cause of malignant biliary obstruction is pancreatic adenocarcinoma. Gallbladder carcinoma is 9 times more common than bile duct malignancy.

Video Endoscopic Sequence 1 of 2.

The Black Esophagus:

Acute Esophageal Necrosis Syndrome

This is the case of a man of 86 year-old who have a history of malignancy and unspecified surgery, endoscopy found a black esophagus.

The pathogenesis of acute esophageal necrosis (AEN) remains unknown, although ischemia likely has a role based upon histopathologic and clinical data. In support of this hypothesis is the observation that temporary reduction of esophageal blood perfusion can result in extensive esophageal necrosis, which resolves rapidly when perfusion is restored. Furthermore, AEN tends to occur in the distal third of the esophagus, which is relatively hypovascular compared with other esophageal segments. Finally, the necrosis of the mucosa and submucosa, microscopic thrombosis and rapid regression are similar to the changes seen in ischemic colitis.

Video Endoscopic Sequence 2 of 2.

Endoscopy of The Black Esophagus

A narrowing in the duodenum with an ulcer and remains of surgical threads is observed.

Gastric outlet obstruction has also been implicated in the pathogenesis of AEN. Regardless of cause, gastric outlet obstruction leads to an accumulation of fluid in the stomach, which can promote esophageal reflux. Exposure of the esophageal mucosa to acid could overwhelm the physiologic defense mechanisms resulting in direct injury with necrosis.

AEN also has been associated with broad spectrum antibiotics, hyperglycemia, underlying malignancy, herpetic infection, gastric volvulus, Stevens-Johnson syndrome, after prolonged vomiting following alcohol binging, alcoholic lactic acidosis, diabetic ketoacidosis, following upper endoscopy and esophageal manometry/pHmetry, a paraesophageal hernia, alcoholic hepatitis, and aortic dissection

It is highly unlikely that a single etiologic factor is responsible for AEN. The presumed overall understanding is that of a "two hit" phenomenon. There is an initial event (ie, low flow vascular state), which then predisposes the esophageal mucosa to a severe topical injury (ie, reflux of acid and pepsin).

DIAGNOSIS — Diagnosis is established with upper endoscopy. In the initial stages, the esophagus demonstrates the characteristic black discoloration with underlying friable hemorrhagic tissue, and a sharp transition to normal-appearing mucosa at the gastroesophageal junction. As noted above, predilection to the distal third of the esophagus is almost universal, although proximal involvement has been described. As the disease progresses, the esophagus may become partially covered with thick, white exudates that can be dislodged easily to reveal pink granulation tissue. These exudates most likely represent sloughed mucosal cells.

Biopsies should be obtained to differentiate acute esophageal necrosis (AEN) from other conditions in which the esophageal mucosa appears darkened (see below). Microscopic evaluation reveals severe necrosis of the mucosa and submucosa. Inflammation and partial destruction of adjacent muscle fibers may occasionally be seen and blood vessels are sometimes thrombosed or occluded. The rapid development of an eschar may protect the esophagus from complete penetration by whatever irritant is present.