A histopathological study on pyloric ulcer.

After the pyloric ulcer was defined as a peptic ulcer occurring at the pylorus or having its centre in the prepyloric region within 2 cm from the pylorus, its histopathological features were studied on 94 pyloric ulcers in 88 surgically resected stomachs. 72.3 per cent of these ulcers were less than 1.0 cm in diameter. The incidences of UI-II, III and IV ulcers were almost equal, and the majority of UI-II and UI-III ulcers were found in scarring stage in the specimens. These pyloric ulcers were classified into three types according to whether the centre of ulcer is situated above (Type-1), on (Type-2) or below (Type-3) the pylorus. Type-1 ulcers wre the most frequent, their incidence being 70.2 per cent. On histologic examination, it was observed that duodenal gland area extended over the pyloric antrum in 90 per cent of the specimens. Contrary to the mucosal rule of Oi for the genesis of peptic ulcer, pyloric ulcers were located in poric gland gland are in 30.9 per cent and on the glandular boundary in 57.4 per cent. Only in 11.76 per cent, the ulcer developed in duodenal gland area. In 68.2 per cent, pyloric ulcer was associated with other gastric or duodenal ulcers. The majority of these coexisting gastric ulcers occurred in the pyloric gland area adjacent to the antrofundic border, and all the duodenal ulcers in the proximal duodenum. Moderate or severe atrophic changes in gastric antral mucosa were found in a large number of the specimens with coexisting gastric ulcer, whereas the changes were less pronounced in those with pyloric ulcer alone.