Cell proliferation in three types of Barrett's epithelium

Barrett's epithelium is a columnar, possibly premalignant, metaplasia of the oesophagus. To study the pattern of epithelial renewal in this disorder, we localised the lower oesophageal sphincter by manometry in 12 patients with known Barrett's epithelium, obtained multiple suction biopsies above the sphincter, and organ cultured the biopsies over 3H-TdR-containing medium to label proliferating cells. Of 23 biopsies from the 12 patients, 13 were specialised columnar type, three were junctional type, and seven were fundic type. None of the patients showed clinical evidence of oesophageal carcinoma, and oesophageal cytological examinations were uniformly negative for neoplastic cells. When compared with control gastric fundic biopsies from normal volunteers, mean values for the labelling index and the proportion of the pit which was occupied by the proliferative zone in Barrett's biopsies were not significantly different. However, four individual Barrett's biopsies (three specialised columnar type and one junctional type) did have a proliferative zone which occupied a greater proportion of the pit than did the widest control zone. We propose that the pattern of epithelial proliferation in Barrett's epithelium in general is similar to that found in other gastrointestinal columnar epithelia. However, a minority of patients with Barrett's epithelium may have an expanded proliferative zone. The clinical implications of an expanded proliferative zone with regard to the subsequent development of oesophageal carcinoma require further investigation.