Barrett’s esophagus is a condition in which the tissue lining the esophagus – the tube that passes the food from the mouth to the stomach – is replaced by tissue similar to that of the intestinal lining. This occurs chiefly in the cells of the epithelial tissue which lines the lower end of the esophagus.
About 10% of the patients with gastroesophageal reflux may be expected to develop Barrett’s esophagus, and in about 10% of the patients with Barrett’s esophagus, dysplasia occurs.
Dysplasia is a pre-cancerous stage in Barrett’s esophagus, where the cell develops abnormal features. However, these abnormal cells do not have the capability to spread to other parts of the body. Depending upon the grades of dysplasia, treatment options are available.
Characteristics of Dysplasia in Barrett’s Esophagus
Dysplasia in Barrett’s esophagus is histologically classified into two types: “adenoma” and “non‐adenoma‐like” on the basis of the similarity or otherwise of the dysplastic cells to cells found in sporadic colonic adenomas. Other than these, uncommon and atypical forms of dysplasia are also known to occur in epithelium affected both by Barrett’s esophagus and by inflammatory bowel disease.
There are two grades of dysplasia in Barrett’s esophagus: low-grade dysplasia and high-grade dysplasia. These are identified through either endoscopy or biopsy.
Low Grade Dysplasia in Barrett’s Esophagus
If microscopic examination reveals the presence of a few cells with mildly abnormal features, it is termed “low-grade dysplasia” (LGD). This condition is considered as the earliest precancerous stage of the esophageal epithelium. Cells with LGD have crowded nuclei which are elongated, irregular, and hyperchromatic, show prominent chromatin with or without numerous small nucleoli.
Adenomatous LGD is the usual type of dysplasia in Barrett's esophagus. Here the crypts show comparatively preserved glandular architecture or only minimal distortion of nuclear architecture but a normal number of nuclei. Most often, dysplastic nuclei are observed aggregated at the base of the cells. The significance of LGD in Barrett’s esophagus is controversial, but in general, follow-up is recommended.
Diagnosis and Treatment
In low-grade dysplastic BE, the diagnosis might be difficult as there is little difference seen between “indefinite for dysplasia” and LGD in biopsies. However, there are substantial inter- and intra-observer differences in the diagnosis of both these conditions, which are thus combined into one as regards their clinical management.
LGD requires effective treatment of the gastroesophageal reflux with proton pump inhibitors, or PPIs. Maintaining a healthy and balanced diet can also help in reducing the reflux. Regular biopsies are suggested to make sure that the dysplasia will not progress or develop into malignancy. When the dysplasia is no longer seen, endoscopic follow up may be discontinued, but it is wise to continue taking PPIs.
In cases where the acid reflux drugs do not produce adequate response and fail to eliminate the dysplasia, endoscopic eradication therapy (EET) is suggested.
Endoscopic Resection (ER)
- Endoscopic resection (ER) utilizes endoscopic techniques to remove dysplastic tissue. For proper dysplasia assessment, endoscopic resection should be performed only in patients with abnormalities that are visible on endoscopy.
- Generally, most of the suspicious areas of tissue are dissected during endoscopic resection for further analysis.
- Residual areas of dysplasia are removed through the radiofrequency ablation technique.
Radiofrequency Ablation (RFA)
- In the RFA technique, radiofrequency waves are passed through a catheter to remove the diseased tissue in the esophagus without causing too much damage to the healthy neighboring tissues.
- Replacement of abnormal Barrett’s tissue by healthy tissue takes about four weeks with the RFA treatment.
High Grade Dysplasia in Barrett’s Esophagus
High-grade dysplasia (HGD) in Barrett’s esophagus (BE) is a further step on the precancerous continuum of tissue changes before the actual development of an esophageal adenocarcinoma. Barrett’s esophagus that occurs as a complication of gastroesophageal reflux disease (GERD) is an abnormal change that occurs in normal esophageal cells. HGD increases the risk of esophageal adenocarcinoma.
Diagnosis and Treatment
Esophagectomy: This procedure is the removal of the abnormal tissue of Barrett’s esophagus by surgery, and is also used to treat patients with HGD. in this procedure, the whole esophagus is removed and then an artificial organ reconstructed using parts of other organs (usually the stomach).
Endoscopic Mucosal Resection (EMR): This procedure helps to remove abnormal tissue areas in the esophageal mucosa, including HGD. EMR is also frequently used to remove rough HGD areas.
Radiofrequency ablation with Barx ablation: To treat HGD due to Barrett’s esophagus, heat energy is applied to the areas of intestinal metaplasia to ablate the abnormal cells in the esophagus.
Photodynamic Therapy (PDT): It is a kind of treatment for HGD which uses light energy to remove the diseased cells in esophagus, following their pretreatment with a sensitizing chemical.
Cryotherapy: This process involves spraying of liquid nitrogen or carbon dioxide onto the esophageal mucosa, which freezes the BE and HGD.
Reviewed by Liji Thomas, MD.