[Analysis of clinical and endoscopic characteristics of cap polyposis in children].

Objective: To summarize the clinical features, endoscopic characteristics, treatment and prognosis of cap polyposis (CP) in children. Methods: In this case series study, clinical data including clinical manifestations, laboratory tests, endoscopic examinations, pathological results, treatment plans and follow-up conditions of 6 CP children diagnosed at Xi'an Children's Hospital from January 2018 to August 2025 were summarized. Results: Among the 6 children, there were 5 males and 1 female, with the age range at diagnosis of 9.2 to 14.3 years. The symptoms included bloody stool in all 6 cases, diarrhea in 4 cases, prolapse of perianal masses in 2 cases, and malnutrition in 2 cases. Among the auxiliary examinations, 3 cases were positive for 13C-urea breath test, and 5 cases were positive for Helicobacter pylori (Hp) in gastric mucosa histopathology. Colonoscopy revealed irregular polyps covered with white mucus, with 3 cases involving the rectum and 3 cases involving both the rectum and sigmoid colon. Histopathology showed inflammatory polyps covered with fibrous purulent exudate. The treatment plan included Hp eradication, mesalazine, hormone enema, thalidomide, and endoscopic polypectomy. The symptoms of all 6 children improved. Five of the children underwent re-examination with colonoscopy. Among them, 3 cases showed small polyp-like protrusions, and 2 cases showed local intestinal mucosa with slight congestion. Conclusions: CP is rare in children, with hematochezia and diarrhea as the main clinical manifestations. Colonoscopy typically reveals polyps with mucus adhering to the surface. Diagnosis requires histopathological examination, and individualized treatment should be formulated based on the specific condition of the child.