Intestinal metaplasia and the squamocolumnar junction: what does it all mean?
- Chairman and Professor of Medicine,
- Department of Gastroenterology,
- The Cleveland Clinic Foundation,
- 9500 Euclid Avenue, S40,
- Cleveland, Ohio 44195, USA
See article on page 659
In theory, the diagnosis of Barrett’s oesophagus should be fairly simple, namely the presence of intestinal metaplasia anywhere in the tubular oesophagus. However, recognising where the tubular oesophagus ends and the saccular stomach begins is fraught with difficulty. The precise junction may be difficult to identify endoscopically because of the presence of a hiatus hernia, inflammation and some disassociation between the squamocolumnar junction and the lower oesophageal sphincter zone in normal individuals. Histologically, the squamous mucosa of the oesophagus accurately defines this area, but distinguishing normal gastric cardia and metaplastic changes of the distal oesophagus may be difficult. Normally, the mucosa of the cardia is composed of tightly packed mucus secreting glands with a lamina propria devoid of any significant inflammatory component. On occasion, biopsy specimens from the cardia show an increase in the amount of acute and chronic inflammatory cells, a condition termed carditis. The cardia can also have associated areas of intestinal metaplasia with goblet cells, histologically similar to the well described intestinal metaplasia in the distal stomach or classically defined as Barrett’s oesophagus when located in the tubular oesophagus. Finally, structures just do not sit still in the oesophagus during endoscopy, making precise location and biopsy even more difficult. Thus, it is difficult to know in every case whether the intestinal metaplasia is from the distal oesophagus or from the cardia.
The classic definition of Barrett’s oesophagus requiring the presence of at least …