Abstract
Reflux oesophagitis may be accompanied by replacement of squamous epithelium by columnar epithelium (Barrett's oesophagus). The columnar epithelium may resemble either gastric or intestinal mucosa, though ultrastructural and histochemical studies indicate that the intestinal type does not necessarily resemble normal small intestine. Twenty-two malignant and 10 benign oesophageal specimens were examined histologically and by mucin histochemistry in an attempt to classify the various types of columnar epithelium. An incompletely differentiated variant of intestinal metaplasia secreting sulphomucins was associated with well but not poorly differentiated adenocarcinomas (p less than 0.02; Fisher's exact test). Similar findings have been described in the stomach and incomplete intestinal metaplasia may be related to disorders of growth and differentiation described in other sites such as the colon. These observations may help in the interpretation of oesophageal biopsies, possibly permitting identification of patients at risk of developing oesophageal adenocarcinoma.