The antral nipple sign of pyloric mucosal prolapse: endoscopic correlation of a new sonographic observation in patients with pyloric stenosis.

This study describes the antral nipple sign of pyloric mucosal prolapse, a newly delineated sonographic observation in patients with pyloric stenosis, correlates the endoscopic findings, and examines its prevalence and significance in 31 consecutive patients with pyloric stenosis. Fifty patients who did not have pyloric stenosis served as the control population. The antral nipple sign consists of visualization of prolapsed, hypertrophied pyloric mucosa protruding into the gastric antrum. Using the Wilcoxon scores (rank sums), there was no significant difference among the patients in age, weight, or pyloric muscle dimensions. Although the diagnosis of pyloric stenosis is made on the basis of muscle thickness, we have documented that the pyloric mucosa becomes redundant in infants with pyloric stenosis, permitting a fuller understanding of the anatomic correlate underlying the sonographic images.