Barretts esophagus is a condition in which there is an abnormal (metaplastic) change in the mucosal cells lining the lower portion of the esophagus, from stratified squamous epithelium to simple columnar epithelium with interspersed goblet cells that are normally present only in the small intestine and large intestine. This change is considered to be a premalignant condition because it is associated with a high incidence of further transition to esophageal adenocarcinoma, an often-deadly cancer.The main cause of Barretts esophagus is thought to be an adaptation to chronic acid exposure from reflux esophagitis. Barretts esophagus is diagnosed by endoscopy: observing the characteristic appearance of this condition by direct inspection of the lower esophagus; followed by microscopic examination of tissue from the affected area obtained from biopsy. The cells of Barretts esophagus are classified into four categories: nondysplastic, low-grade dysplasia, high-grade dysplasia, and frank carcinoma. High-grade dysplasia and early stages of adenocarcinoma may be treated by endoscopic resection or radiofrequency ablation. Later stages of adenocarcinoma may be treated with surgical resection or palliation. Those with nondysplastic or low-grade dysplasia are managed by annual observation with endoscopy, or treatment with radiofrequency ablation. In high-grade dysplasia, the risk of developing cancer might be at 10% per patient-year or greater.The incidence of esophageal adenocarcinoma has increased substantially in the Western world in recent years. The condition is found in 5–15% of patients who seek medical care for heartburn (gastroesophageal reflux disease, or GERD), although a large subgroup of patients with Barretts esophagus are asymptomatic.
Since the COVID-19 pandemic In Scotland, the local NHS started using a swallowable sponge (Cytosponge) in hospitals to collect cell samples for diagnosis. Preliminary studies have shown this diagnostic test to be a useful tool for screening people with heartburn symptoms and improved diagnosis. Intestinal metaplasia
The presence of goblet cells, called intestinal metaplasia, is necessary to make a diagnosis of Barretts esophagus. This frequently occurs in the presence of other metaplastic columnar cells, but only the presence of goblet cells is diagnostic. The metaplasia is grossly visible through a gastroscope, but biopsy specimens must be examined under a microscope to determine whether cells are gastric or colonic in nature. Colonic metaplasia is usually identified by finding goblet cells in the epithelium and is necessary for the true diagnosis.Many histologic mimics of Barretts esophagus are known (i.e. goblet cells occurring in the transitional epithelium of normal esophageal submucosal gland ducts, "pseudogoblet cells" in which abundant foveolar [gastric] type mucin simulates the acid mucin true goblet cells). Assessment of relationship to submucosal glands and transitional-type epithelium with examination of multiple levels through the tissue may allow the pathologist to reliably distinguish between goblet cells of submucosal gland ducts and true Barretts esophagus (specialized columnar metaplasia). The histochemical stain Alcian blue pH 2.5 is also frequently used to distinguish true intestinal-type mucins from their histologic mimics. Recently, immunohistochemical analysis with antibodies to CDX-2 (specific for mid and hindgut intestinal derivation) has also been used to identify true intestinal-type metaplastic cells.