title: Histology of gastroesophageal junction in fetal and pediatric autopsy.
abstract: BACKGROUND
  There is much debate over whether the gastric cardia exists from birth as a normal structure or is a metaplastic structure that develops as the result of gastroesophageal reflux disease. This question has become a matter of concern since the incidence of adenocarcinoma at the gastroesophageal junction has been increasing rapidly in the Western world for more than 2 decades. Various groups of investigators have tried to clarify this matter by examining the histology of the gastroesophageal junction in autopsy cases, and there have been striking discrepancies in their findings. In one group, it was observed that cardiac mucosa was present in all pediatric autopsies. On the contrary, another group concluded that pure cardiac mucosa was absent in 56% of their autopsy cases.
  
  
  OBJECTIVE
  Without regard to the definition of the cardiac mucosa, we focused on the distance between the squamocolumnar junction and the most proximal parietal cells to elucidate the histologic features of the gastroesophageal junction on the gastric side.
  
  
  METHODS
  The entire gastroesophageal junction and the proximal part of the stomach from 23 fetal and pediatric autopsies were mapped. We measured the distance from the squamocolumnar junction to the most proximal parietal cells identified. The extent of the transitional zone, defined as the mucosa between the squamocolumnar junction and the fundic mucosa, was also evaluated.
  
  
  RESULTS
  The transitional zone was identified in 78% of cases, and it always harbored some scattered parietal cells in mucous glands. The parietal cells were consistently identified adjacent to the squamocolumnar junction in all cases. Although the transitional zone in fetal stomach was usually composed of several pits of foveolar epithelium without glandular portions, it contained glandular structures in the pediatric cases.
  
  
  CONCLUSIONS
  The mucosa composed of pure mucous cells does not exist as a normal developmental structure.
authors.affiliation: Department of Pathology, Seoul National University College of Medicine and Seoul National University Hospital Clinical Research Institute, Seoul, Korea.
authors.forename: Young S
authors.initials: YS
authors.lastname: Park
authors.forename: Hyo Jin
authors.initials: HJ
authors.lastname: Park
authors.forename: Gyeong Hoon
authors.initials: GH
authors.lastname: Kang
authors.forename: Chong Jai
authors.initials: CJ
authors.lastname: Kim
authors.forename: Je G
authors.initials: JG
authors.lastname: Chi
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology; D000293:Adolescent; D001344:Autopsy; D002299:Cardia / Q000473:pathology; D002454:Cell Differentiation / Q000502:physiology; D002648:Child; D002675:Child, Preschool; D005314:Embryonic and Fetal Development; D004848:Epithelium / Q000473:pathology; D004943:Esophagogastric Junction / Q000473:pathology*; D005260:Female; D005313:Fetal Death / Q000473:pathology*; D005753:Gastric Mucosa / Q000473:pathology; D005764:Gastroesophageal Reflux / Q000473:pathology; D005865:Gestational Age; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D010295:Parietal Cells, Gastric / Q000473:pathology; D010372:Pediatrics; D011247:Pregnancy; D011446:Prospective Studies; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000473:pathology