Brief Article
Copyright ©2013 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Jul 14, 2013; 19(26): 4185-4191
Published online Jul 14, 2013. doi: 10.3748/wjg.v19.i26.4185
Cap polyposis: A rare cause of rectal bleeding in children
Jia Hui Li, May Ying Leong, Kong Boo Phua, Yee Low, Ajmal Kader, Veena Logarajah, Lin Yin Ong, Joyce HY Chua, Christina Ong
Jia Hui Li, Kong Boo Phua, Ajmal Kader, Veena Logarajah, Christina Ong, Gastroenterology Service, Department of Pediatric Medicine, KK Women’s and Children’s Hospital, Singapore 229899, Singapore
May Ying Leong, Department of Pathology, KK Women’s and Children’s Hospital, Singapore 229899, Singapore
Yee Low, Lin Yin Ong, Joyce HY Chua, Department of Pediatric Surgery, KK Hospital, Singapore 229899, Singapore
Author contributions: Li JH analyzed the cases, conducted the literature review, drafted the initial manuscript, and approved the final manuscript as submitted; Leong MY, Phua KB, Low Y, Kader A, Logarajah V, Ong LY and Chua JHY critically reviewed and revised the manuscript and approved the final manuscript as submitted; Ong C conceived of the concept, critically reviewed and revised the manuscript and approved the final manuscript as submitted.
Correspondence to: Dr. Christina Ong, Gastroenterology Service, Department of Pediatric Medicine, KK Women's and Children's Hospital, Level 5, Children's Tower, 100 Bukit Timah Road, Singapore 229899, Singapore. christina.ong@kkh.com.sg
Telephone: +65-639-42389 Fax: +65-639-41973
Received: January 22, 2013
Revised: May 1, 2013
Accepted: May 17, 2013
Published online: July 14, 2013
Abstract

AIM: To evaluate the clinicopathological features and treatment outcomes of cap polyposis in the pediatric population.

METHODS: All pediatric patients with histologically proven diagnosis of cap polyposis were identified from our endoscopy and histology database over a 12 year period from 2000-2012 at our tertiary pediatric center, KK Women’s and Children’s Hospital in Singapore. The case records of these patients were retrospectively reviewed. The demographics, clinical course, laboratory results, endoscopic and histopathological features, treatments, and outcomes were analyzed. The study protocol was approved by the hospital institutional review board. The histological slides were reviewed by a pediatric histopathologist to confirm the diagnosis of cap polyposis.

RESULTS: Eleven patients were diagnosed with cap polyposis. The median patient age was 13 years (range 5-17 years); the sample included 7 males and 4 females. All of the patients presented with bloody stools. Seven patients (63%) had constipation, while 4 patients (36%) had diarrhea. All of the patients underwent colonoscopy and polypectomies (excluding 1 patient who refused polypectomy). The macroscopic findings were of polypoid lesions covered by fibrinopurulent exudates with normal intervening mucosa. The rectum was the most common involvement site (n = 9, 82%), followed by the rectosigmoid colon (n = 3, 18%). Five (45%) patients had fewer than 5 polyps, and 6 patients (65%) had multiple polyps. Histological examination of these polyps showed surface ulcerations with a cap of fibrin inflammatory exudate. Four (80%) patients with fewer than 5 polyps had complete resolution of symptoms following the polypectomy. One patient who did not consent to the polypectomy had resolution of symptoms after being treated with sulphasalazine. All 6 patients with multiple polyps experienced recurrence of bloody stools on follow-up (mean = 28 mo).

CONCLUSION: Cap polyposis is a rare and under-recognised cause of rectal bleeding in children. Our study has characterized the disease phenotype and treatment outcomes in a pediatric cohort.

Keywords: Cap polyposis, Polyps, Rectal bleeding, Pediatrics, Inflammatory bowel disease

Core tip: Cap polyposis is a rare and under-recognized condition with distinct clinical, endoscopic and histopathological features. All children with cap polyposis invariably present with rectal bleeding. Awareness of this diagnosis is important as its clinical and endoscopic features can mimic inflammatory bowel disease resulting in prolonged and inappropriate treatment. This article evaluates the clinicopathological features and treatment outcomes in a series of children with cap polyposis. Complete polypectomy should be performed where possible in combination with medical therapy. Prognosis is good for children with few polyps although recurrence rate is high in those with multiple polyps at diagnosis requiring further surgical intervention.