A clinicopathological study of post-bulbar duodenal ulcer--analysis of 6 cases and comparison to usual chronic duodenal ulcer.

We investigated the functional and morphological aspects of acid secretion in 6 patients with post-bulbar duodenal ulcer and compared the findings with the events of 40 patients with the usual chronic duodenal ulcer. The post-bulbar ulcer patients showed a much higher acidity, and a biphasic, prolonged acid secretion pattern, presumably representing an enhanced parietal cell function. Histological study of antrectomized specimens revealed that 4 of those with the post-bulbar ulcer had a small antrum in which the fundic gland area expanded distally. The proximal border of the pyloric gland area was within 4 cm of the pylorus. This would suggest the presence of a large parietal cell mass. On the contrary, however, there was no such instance in those patients with the usual duodenal ulcer. Hyperacidity, due to a large parietal cell mass and an enhanced parietal cell function, may play an important role in the pathogenesis of post-bulbar duodenal ulcer.