Non-neoplastic anomalies
Congenital pyloric stenosis

Author: Elliot Weisenberg, M.D.(see Authors page)

Revised: 7 April 2016, last major update July 2012

Copyright: (c) 2003-2016,, Inc.

See also: Acquired pyloric stenosis
Cite this page: Congenital pyloric stenosis. website. Accessed August 17th, 2018.
Definition / general
  • Common congenital abnormality (1 per 300-900 births)
  • 75% male, onset at 3-12 weeks, high concordance in monozygotic twins, associated with Turner syndrome, trisomy 18, esophageal atresia
Clinical features
  • Persistent projectile non-bilious vomiting in second week of life
  • Regurgitation, visible peristalsis
  • Pyloromyotomy (splitting of pyloric muscle)
Gross description
  • Thickened pyloric muscle resembling a fusiform mass, 3-5 cm, that occludes the pyloric channel
Gross images
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Thickened muscularis propria
Contributed by Dr. Raul S. Gonzalez, M.D.

Hypertrophic pyloric stenosis

Microscopic (histologic) description
  • Edema and inflammatory changes in mucosa or submucosa
  • Thickening primarily of circular muscle, which terminates abruptly distally