Ectopic Mucosa - Causes, Symptoms, and Treatment

Introduction

Ectopic gastric mucosa, which lies in the esophagus, is considered a residue of the columnar epithelium of the embryonic esophagus. Replacement of the columnar epithelium by an SSE (stratified squamous epithelium) in the mid-esophagus and extends distally and proximally. Cancer can rarely occur with this condition. The heterotopic gastric mucosa is considered to be a benign disease. It is also called gastric heterotopia, a cervical inlet patch. It is the most common type of heterotopia. It is usually found in the postcricoid region (a region that is difficult to examine endoscopically) and is found in one to four percent of cases endoscopically. Ectopic mucosa mostly occurs due to the rest of gastric precursor cells, which remain after an original esophageal mucosa that is replaced by a stratified squamous epithelium. It is usually classified on the basis of symptoms and morphogenic changes.

What Is the Pathogenesis of Ectopic Mucosa?

The ectopic gastric mucosa patches are endoscopically recognized in the upper esophagus as an oval salmon-pink patch. The prevalence of ‘inlet patches’ is widely seen. This can be underdiagnosed in routine endoscopy as an examination of the upper esophagus and not performed by healthcare providers in the absence of symptoms like dysphagia. The highest prevalence was found in those areas. In children, the condition is seen in 21 percent of cases. The pathogenesis of ectopic gastric mucosa is a matter of debate embryological- congenital- and acquired - consecutive to GERD (gastroesophageal reflux) like Barrett's esophagus. The incidence is higher in children, particularly in the first year of infection, and it declines with advancing years. Patches are frequently observed in the upper esophagus and in other lower esophageal conditions, such as esophagitis, Barrett's esophagus, and hiatal hernia.

How Common Is the Occurrence of Ectopic Mucosa?

The ectopic mucosa is mostly determined by radiographic detection or accidentally diagnosed via an endoscopic method. The prevalence of ectopic mucosa in the upper esophagus is 2.4 percent. The lesions are more common in men than women and more common in the right wall than in the left wall of the esophagus. Around 3.1 percent in men and 0.6 percent in women. According to the radiographic feature, a pair of indentations along the lateral margin of the esophagus is found with a rim-like shadow on the anterior and posterior walls. Recognizing ectopic mucosa's main characteristic radiographic feature results in finding abnormalities and follow-up endoscopy.

What Is the Connection Between Ectopic Mucosa and Meckel’s Diverticulum?

Meckel’s diverticulum is the most common congenital abnormality found in the gastrointestinal tract, and it affects around one to three percent of the overall population. It occurs as a result of the failure of regression of the omphalomesenteric duct. In these cases, the duct is frequently located within 100 cm proximal from the ileocecal valve and thus, resulting in symptoms related to the lower abdomen. In most cases, they are asymptomatic, only around 25 percent of cases exhibit relevant symptoms.

• The conditions include complications like intestinal obstruction, bleeding vesica diverticular fistula (it is an abnormal connection that develops between the colon and the bladder), tumors (abnormal tissue mass), and diverticulitis (conditions where bulging small pouches develop in the digestive tract).

• An ectopic mucosa is one of the most common complications of Meckel’s diverticulum, mainly in cases younger than two years of age.

• Ectopic mucosa is present in around 20 percent of cases of Meckel's diverticulum. And can also be rarely found in cases of gastrointestinal duplication.

What Are the Complications of Ectopic Mucosa in the Upper Esophagus?

The complications of ectopic mucosa in the upper esophagus are

• Dysphagia (difficulty in swallowing).

• Odynophagia (pain while swallowing).

• Stricture and web.

• Nausea and vomiting.

• Burning sensation.

• Fistula.

• Inflammation.

• Peptic ulcerations.

The ectopic gastric mucosa is capable of secreting acid, which is monitored by pH monitoring. Gastritis (inflammation of the mucosal lining of the stomach) and Helicobacter pylori colonization are rare complications of the ectopic gastric mucosa.

How Is the Diagnosis of Ectopic Mucosa in the Upper Esophagus Made?

Ectopic mucosa is mostly diagnosed during an endoscopy. It is further analyzed by radiography and can also be confirmed by biopsies. Biopsies are performed in order to confirm its malignant potentiality.

Endoscopy: By this technique, a round to oval, reddish-orange salmon flat patch similar to an inlet patch is detected that confirms the presence of ectopic mucosa.

99 Tc Pertechnetate Scintigraphy: This test evaluates ectopic gastric mucosa. This test visualizes gastric duplication simultaneously with the stomach, while intestinal duplication tracer activity can be seen in a dynamic sequence, even before gastric tracer visualization.

How Are Areas of Ectopic Mucosa in the Upper Esophagus Treated?

Ectopic gastric mucosa has been treated in a few complicated and symptomatic cases. There is a lack of large series. H2 antagonists and proton pump inhibitors are used successfully in benign cases and acid-related symptoms.

• CO2 laser therapy or endoscopic dilation therapy is performed in cases of structuring lesions. In individuals with a structuring patch, endoscopic thermal coagulation of ectopic gastric mucosa is combined with Omeprazole therapy. This technique is interestingly followed by the regeneration of normal squamous epithelium.

• In complicated cases along with adenocarcinoma, surgery is the only option.

• Other therapeutic options include other methods used in treating Barrett's esophagus and superficial esophageal cancer, such as ablation therapy, photodynamic therapy, electrocoagulation, and Nd: YAG laser therapy.

What Is the Differential Diagnosis of Ectopic Mucosa?

Differential diagnosis of ectopic mucosa may include the following conditions:

• Peptic Ulcer Disease: This is a condition in which open sores develop in the lining of the stomach or duodenum. Peptic ulcers can cause abdominal pain, nausea, and other symptoms.

• Esophageal Cancer: This is a type of cancer that can develop in the lining of the esophagus. Ectopic mucosa can be a risk factor for the development of esophageal cancer.

• Achalasia: This is a condition in which the muscles of the esophagus do not function properly, leading to difficulty swallowing and regurgitation.

• Gastroesophageal Reflux Disease (GERD): This is a condition in which the contents of the stomach, including acid, flow back up into the esophagus, causing heartburn and other symptoms.

• Barrett's Esophagus: This is a condition in which the normal tissue lining the esophagus is replaced by a type of tissue that is usually found in the intestines. Barrett's esophagus is associated with an increased risk of esophageal cancer.

• Gastric Heterotopia: This is a rare condition in which gastric tissue is found in abnormal locations, such as in the esophagus or duodenum.

Conclusion

Due to its rare occurrence, ectopic gastric mucosa and the associated complications have scarce literature. The neoplastic potential of the condition remains unknown. Thus, it is difficult to provide treatment and surveillance. In most cases, ectopic gastric mucosa is spotted during an upper endoscopy. Biopsies are taken to detect intestinal metaplasia and dysplasia. Individuals with benign conditions should be treated based on endoscopic and clinical features.