Benign Disease of the Esophagus

Esophageal Rings and Webs

Esophageal rings and webs are growths of tissue that partially obstruct the lumen of the esophagus. The prevalence of esophageal rings and webs has not been determined, as most patients are asymptomatic. Most lesions are found incidentally at the time of a radiologic study or endoscopy in 18%. No consensus exists as to the cause, location, or significance of the rings.

Rings are categorized as “A” and “B,” formerly known as Shatzki rings ( Fig. 4.1 ). They are most common distally but may occur along the entire length of the esophagus. The structure described as an “A” ring is believed to be a normal smooth muscle contraction of the distal esophagus located at the gastroesophageal junction (GEJ). “A” rings are rare and found mostly in children at the time of a barium swallow or esophagogastroduodenoscopy (EGD). Symptomatic patients present with intermittent dysphagia to solid food.

In 1953, Schatzki first reported a circumferential stricture, or ring, at the GEJ known as a “B” ring. It is composed of the connective tissue and the muscularis mucosa at the squamocolumnar junction and is less than 0.5 cm in length. It has also been attributed to the impression of the diaphragm at the LES. Barium esophagrams performed for symptom of dysphagia demonstrate esophageal “B” rings in 6% to 14% of patients. They are associated with hiatal hernias in 97% patients. Of patients with a Schatzki “B” ring, 65% have reflux, 50% erosive esophagitis, and 25% have a nonspecific dysmotility disorder. It is believed that over time, a ring may progress to form a stricture.

The differential diagnosis of a ring includes a congenital web, gastroesophageal reflux disease, or carcinoma-induced strictures. Eosinophilic esophagitis and reflux may play a role in the development of a Schatzki or “B” ring. Some evidence indicates that a ring may have a protective effect from Barrett esophagus. A Schatzki or “B” ring may be a rare cause of swallow syncope.

An esophageal web is less than 2 mm in diameter and encroaches on the esophageal lumen. It is covered with squamous epithelium and is most commonly found at the cricoid location of the cervical esophagus. The cause of esophageal webs is unknown but they have been thought to be due to chronic GERD. Evidence of reflux as an origin suggests that webs may progress to strictures if reflux is untreated. Congenital development has also been suggested. Webs may be associated with a Zenker diverticulum, iron-deficiency anemia, and chronic graft-versus-host disease following bone marrow transplantation. Webs may also be an extracutaneous manifestation in 14% to 33% of patients with epidermolysis bullosa, bullous pemphigoid, and pemphigus vulgaris.