To investigate the distribution and specificity of intestinal metaplasia (IM) in columnar lined esophagus (CLE), the authors reviewed biopsies of the hiatal hernia pouch (HHP) and esophagus from 17 patients with CLE (84 biopsies) and 10 controls (25 biopsies). The proximal margin of the gastric folds was used as an endoscopic landmark, corresponding to the gastroesophageal muscular junction (GEMJ). No biopsies obtained above the GEMJ in control patients showed columnar mucosa. No goblet cell metaplasia was seen in 21 biopsies of the HHP from patients with CLE or in 13 corresponding biopsies from controls. In contrast, alcian blue (AB) stains showed diffuse acid mucins in 3 of 21 biopsies of the HHP from patients with CLE and in 10 of 13 corresponding biopsies from controls, demonstrating that goblet cell metaplasia clearly distinguishes biopsies of CLE from the HHP (P less than 0.01), whereas small amounts of diffuse acid mucin on AB stains do not. IM evidenced by goblet cell metaplasia was frequently seen in biopsies only 2-3 cm above the GEMJ, and CLE was limited to that area in three patients, suggesting that the distal esophagus cannot be dismissed as a site for metaplastic and possibly premalignant mucosa. Adenocarcinoma was diagnosed during the course of the study in one patient with only 5 cm of columnar mucosa above the GEMJ.