César A. Blanco-Becerra; Fabián A. Gómez-Torres & Luis E. Ballesteros-Acuña

Barrett's esophagus is a condition where the distal third of the esophagus changes its epithelial lining from non- keratinized stratified squamous to simple columnar. This cross-sectional descriptive study was conducted to characterize the esophageal mucosa in the third trimester of pregnancy and determine possible variants in its development and was carried out in the Morphology Laboratory of the Health Faculty of the Industrial University of Santander, Colombia, with 45 human fetuses in the third trimester of gestation (weeks 25-40). A section of the distal esophagus and the first portion of the cardial region of the stomach were obtained, and the histological sections were subjected to a fixation process with 5 % formaldehyde solution. The sections were stained with hematoxylin and eosin and were evaluated for the presence of epithelial change or glands in the esophageal lamina propria. The change from non- keratinized stratified squamous epithelium to simple columnar epithelium was observed in the esophageal mucosa in five fetuses (11.1 %). In 15 cases (33.3 %), the presence of mucous glands underlying the epithelium was determined. In two fetuses, simple columnar epithelium was observed in the esophageal mucosa and underlying submucosal glands (4.4 %). The lack of replacement of the columnar epithelium by squamous epithelium in the distal third of the esophagus and the presence of mucous glands in the last third of gestation may suggest the presentation of Barret's esophagus in adulthood and thus, a predisposition to develop esophageal adenocarcinoma.

KEY WORDS: Barrett's esophagus; Adenocarcinoma; Fetuses; Epithelium.

BLANCO-BECERRA, C. A.; GÓMEZ-TORRES, F. A. & BALLESTEROS-ACUÑA, L. E. The variation of the fetal esophageal mucosa at the end of gestation may be a possible etiopathogenic factor for Barrett’s esophagus. Int. J. Morphol., 42(2):234-238, 2024.