Chronic obstruction of the antrum of the stomach by a mucosal diaphragm, with malnutrition, impairment of growth and secondary small intestine damage.

SOMETIMES the antrum of the stomach is almost occluded by a thin mucosal membrane or diaphragm stretched across the lumen. A central aperture, often very small, allows slow imperfect emptying of the upper loculus (which comprises most of the stomach) into the distal antrum, and into the duodenum. If nutrition is maintained at all, the level at which it is maintained depends on the size of the central aperture. There is no ulceration and no other abnormality, and as a rule no cause for the presence of the membrane is evident. The lesion is not related to the concentric contraction and canalising of the antrum seen in chronic simple ulceration of the antrum, nor is it related to cryptogenic hypertrophy of the antral muscle. It is not a pre-malignant lesion. It has to be distinguished from mucosal diaphragm at or in the pyloric (gastroduodenal) channel (Rhind 1959). That also produces chronic obstruction, but it shows a different appearance on barium X-ray plates. Ewald (1892) described a lesion in the neighbourhood of the "pylorus" as a possible cause of dilatation of the stomach. "Sometimes a regular ring is found, so that when the stomach is opened it looks as if a cord had been drawn underneath the mucous membrane". Riegel (1897) described a "mucosal duplication" as a cause of "pyloric" stenosis and ectasia of the stomach. Probably these were antral mucosal diaphragms. More recently antral mucosal diaphragm has often been reported (Sames, 1949; Parrish et al., 1966; Banks et al., 1967; Parrish et al., 1968) and discussed (Smith and Tuttle, 1969), but needs to be better known.