Adult Idiopathic Hypertrophic Pyloric Stenosis

To the editor, A 22-year-old male, weighing 55 kg and measuring 160 cm in height, was admitted with a 1-month history of recurrent postprandial vomiting, which could be partially relieved by defecation and passage of flatus. He had no prior history of peptic ulcer and had never undergone upper gastrointestinal endoscopy. Laboratory tests revealed no significant findings. Abdominal computed tomography scans revealed focal mucosal thickening in the gastric fundus and body. Gastrointestinal contrast radiography demonstrated annular stenosis in the prepyloric region, narrowing of the pyloric canal, and incomplete obstruction of the upper gastrointestinal tract (Figure 1A). Esophagogastroduodenoscopy confirmed pyloric obstruction (Figure 1B), leading to a diagnosis of adult idiopathic hypertrophic pyloric stenosis (AIHPS). Conservative management, including proton pump inhibitors and prokinetics, failed to alleviate his symptoms. Subsequently, he underwent two sessions of endoscopic balloon dilation over the following 2 months (Figure 1C,D). However, his symptoms recurred shortly after each procedure, and his weight decreased to 50 kg. After a multidisciplinary team discussion, the patient and his family opted for laparoscopic-assisted distal subtotal gastrectomy with overlap gastrojejunostomy and end-to-side jejunojejunostomy. Histopathological examination revealed a few glands showing mild dysplasia but no evidence of malignancy (Figure 2), which confirmed the diagnosis of AIHPS. He recovered well postoperatively and remained asymptomatic at the 6-month follow-up. Findings of gastrointestinal radiography and endoscopy in this patient. (A) Gastrointestinal radiography showed annular stenosis in the prepyloric region, narrowing of the pyloric canal, and incomplete obstruction. (B) Endoscopy revealed pyloric stenosis and deformation. (C) Endoscopic balloon dilation was performed for pyloric stenosis. (D) Pyloric obstruction was alleviated after endoscopic balloon dilation. Histopathological examination revealed a few glands showing mild dysplasia but no evidence of malignancy. AIHPS is a rare disorder characterized by hypertrophy of the pyloric circular muscle layer, but its etiology remains unclear. Its clinical manifestations are nonspecific, including postprandial vomiting, abdominal distension, and pain. Thus, it is frequently misdiagnosed as functional dyspepsia or gastroparesis. Its diagnosis is initially based on imaging and endoscopic findings. However, histopathology remains the gold standard, revealing a markedly elongated and thickened pylorus. Microscopically, marked hypertrophy and hyperplasia of the gastric muscularis propria are observed, with no significant inflammatory cell infiltration or evidence of malignancy [1, 2]. Treatment options for AIHPS include pyloromyotomy and surgical resection. However, nonsurgical approaches, such as endoscopic balloon dilation, are of limited efficacy with high recurrence rates and are generally reserved for high-risk patients [3]. Because balloon dilation may tear the muscle fibers but not remove the underlying hypertrophic lesion, it can lead to scar formation and even restenosis. Currently, treatment protocols for AIHPS should be further standardized [4]. Yunpeng Shao: writing – original draft, writing – review and editing. Cong Gao: writing – review and editing. Xingshun Qi: conceptualization, supervision, writing – original draft, writing – review and editing, guarantor of the article. All authors have made an intellectual contribution to the manuscript and approved the submission. This work was supported by the Independent Research Funding of General Hospital of Northern Theater Command (ZZKY2024018). The study protocol was approved by the Medical Ethics Committee of our Hospital [Y (2025)464]. Xingshun Qi is a member of the Editorial Board of Gut Medicine and a co-author of this article. He was excluded from all editorial decisions regarding the acceptance of this article for publication. The data that support the findings of this study are available from the corresponding author upon reasonable request.