Autopsy examination in a case of esophageal intramural pseudodiverticulosis revealed that the diverticula were squamous epithelium-lined metaplastic derivatives of esophageal adnexal glands which were present in excessive numbers throughout the length of the esophagus. The basic lesion was congenital or acquired adenosis predisposing to chronic inflammation, resulting in cystic dilatation and squamous metaplasia.