The development of hypertrophic pyloric stenosis in a patient with prostaglandin-induced foveolar hyperplasia

Background Hypertrophic pyloric stenosis (HPS) has been described in associ ation with several obstructive antropyloric lesions including idiopathic fo veolar hyperplasia (gastric mucosal hypertrophy), feeding tubes, eosinophil ic gastroenteritis, and hypertrophic antral polyps. Non obstructive antral webs have also been described with HPS. Patient and methods. We present a case of gastric-outlet obstruction in ass ociation with HPS, namely, prostaglandin-induced foveolar hyperplasia. This entity has been previously described, but rarely in association with HPS. We report a female infant requiring prostaglandin therapy for pulmonary atr esia who developed dose-related prostaglandin-induced foveolar hyperplasia and symptoms of progressive non-bilious vomiting. Results. Intially, ultrasonography demonstrated evidence of antral mucosal hypertrophy as the cause for gastric-outlet obstruction. The patient subseq uently developed progressive thickening of the antropyloric muscle, resulti ng in sonographic appearances of hypertrophic pyloric stenosis. Pyloromyoto my was eventually required for treatment of HPS. Conclusion. A common denominator of most of the above-described entities is thickening and/or hypertrophy of the antral mucosa. We suggest that the an tropyloric musculature may hypertrophy in an effort to overcome the gastric -outlet obstruction caused by the adjacent thickened antral mucosa. In othe r words, these entities may represent examples of "secondary" hypertrophic pyloric stenosis.