Sandbox: esophageal web
Pathogenesis
Inflammation Esophageal webs are thought to be due to the chronic damage to the esophageal mucosa. This is supported by the presence of inflammatory cells in the wall of the web. In allergic esophagitis, eosinophils were found while in cases of chronic inflammation as GERD, lymphocytes prevailed.
Congenital theory Esophageal webs are thought to be due to failure of the esophagus to recanalize. Specimens showed that the esophageal webs contained respiratory epithelium supporting this theory. The webs mostly remain asymptomatic for long times and that is why it is not correlated with being congenital.
Iron deficiency The esophageal webs of Plummer-Vinson syndrome have been associated with iron deficiency anemia in many studies. The exact mechanism by which iron deficiency causes esophageal webs is not known, but it was hypothesized that iron deficiency starts a sequence of events in the esophageal epithelium that ends in its damage and formation of a web. Moreover, treatment of iron deficiency in Plummer-Vinson syndrome patients leads to resolution of dysphagia even before the laboratory results become normal.
Gross picture Esophageal webs appear as an eccentric narrowing of the esophageal lumen (while rings cause circumferential narrowing). Most of the esophageal webs lie anteriorly in the upper part of the esophagus.
Microscopic picture Esophageal webs are covered by esophageal squamous epithelium.
Historical perspective
In 1944, esophageal webs were first described by Templeton and it was thought to be a congenital disease because most of the patients were children. In 1953, a series of case reports of patients having dysphagia and radiological signs denoting esophageal narrowing made the diagnosis of esophageal rings not confined to the pediatric population. In 1968, pathological examination of specimens from the esophageal rings proved that none of them had muscle involvement.
Classification
Type A
Type A esophageal rings describe webs that involve the muscle layer of the esophageal wall and lies in close proximity to the squamocolumnar junction. It is less common than type esophageal webs.
Type B Type B esophageal rings describe the webs that involve only the mucosa and submucosa of the esophagus. It is often named “Schatzki ring”. It is located exactly at the squamocolumnar junction.
Type C Type C esophageal rings refer to wall invaginations due to pressure from the diaphragm. It is rare with no clinical significance.
Causes
Iron deficiency anemia Plummer-Vinson syndrome Celiac sprue Zenker’s diverticulum
Epidermolysis bullosa Bullous pemphigoid Graft versus host disease Pemphigus Vulgaris
Risk factors
Zenker’s diverticulum.
Epidemiology
Prevalence Webs are diagnosed in 5-15% of patients doing barium esophagogram for diagnosing the cause of dysphagia. Congenital esophageal webs are estimated to be 1 in 25,000 to 1 in 50,000 live births.
Race Esophageal webs affects the whites more than other population
Sex Esophageal webs tend to be more common in females. This may be due to the increased prevalence of iron deficiency anemia.
Age Esophageal has no predilection for an age group, however, it is usually not symptomatic until after the age of 40.