Depressed tubular adenoma of the stomach: pathological and immunohistochemical features

We examined 12 depressed tubular adenomas of the stomach pathologically and immunohistochemically in order to clarify the difference between the depressed type and the elevated type. Depressed tubular adenomas showed shallow mucosal depression and, of the 12, nine were endoscopically diagnosed as early gastric cancer. Histologically, the adenoma cells showed dysplasia in varying degree and focal adenocarcinoma occurred in two adenomas measuring over 2 cm. The mean height of the adenoma glands was 0.63 +/- 0.31 mm in the 12 depressed adenomas and 1.32 +/- 0.43 mm in 44 elevated adenomas, while the mean heights of the subjacent mucosa were 0.18 +/- 0.19 mm and 1.07 +/- 0.71 mm, respectively. Thus, depressed adenomas resulted from paucity of the mucosa subjacent to the adenoma glands and the height of the adenomatous glands was half that found in the elevated type. Goblet cells, a variety of endocrine cells and lysozyme-containing cells were found in nine, nine and eight depressed adenomas, respectively, in variable numbers. Hyperplasia of these cells was also detected in depressed adenomas showing mild or moderate dysplasia. Immunohistochemical examination revealed no difference in the phenotypic expression of adenoma cells as between the depressed and the elevated type.