Unusual late-onset hypertrophic pyloric stenosis in an adolescent girl with down syndrome: Case report and review of the literature.

A 16-year-old girl with down syndrome came to our attention for recurrent postprandial vomiting and significant weight loss (>5 kgs). Diagnostic assessment (barium swallow study, ultrasonography, and CT) confirmed hypertrophic pyloric stenosis (HPS). Initial attempt with endoscopic dilation was not successful. The patient underwent Heineke-Mikulicz pyloroplasty. Full oral feeding was achieved by Day 7 postoperatively. At 6-month follow-up, the patient reported relief of symptoms, normal feeding habits and substantial weight gain. HPS should be considered in the differential diagnosis of recurrent vomiting, regardless of age. A comprehensive diagnostic work-up, including ultrasonography, endoscopy, and CT, is recommended to confirm the diagnosis.