• Helicobacter pylori
• cap polyposis
• colonoscopy
• resection
• treatment

• CAP polyposis
• inflammatory bowel disease
• inflammatory granulation tissue
• pathophysiology
• vascular malformation

Cap polyposis (CP) is extremely rare in Japan, and there is no established cure. We report a case in which CP was improved by surgical treatment.

A 48-year-old man was investigated at a local hospital because of diarrhea and bloody stools in 2018. The patient was treated with metronidazole for suspected amoebic dysentery, but his symptoms did not improve. Subsequent close examination revealed possible CP, but treatment with 5-aminosalicylic acid and a steroid enema had no effect. The patient was then referred to our hospital. The bloody stools, diarrhea, and abdominal pain worsened despite medical treatment, so laparoscopic-assisted total proctocolectomy and ileal J-pouch anal anastomosis with ileostomy were performed. CP has no known cause or established treatment, but Helicobacter pylori (HP) infection has been reported in many CP cases in Japan, and HP eradication is often successful. This patient was HP-negative and did not improve with antimicrobial treatment, but the symptoms improved after surgery.

Even after surgery, CP recurrence reportedly occurs within a short period in many cases. However, our patient has had no signs of CP recurrence during 1 year of follow-up.

• Background
• Cap polyposis
• Ileal pouch anal anastomosis
• Laparoscopic surgery

• Cap polyposis
• Children
• Inflammatory polyp
• Rectal polyp
• Rectal prolapse

A 15-year-old adolescent boy presented with chronic constipation, difficulty in defecation, and episodic bloody stools. A rectal mass lesion was digitally palpated. Colonoscopy showed a large circumferential polypoid lesion of the mid-rectum. Snare polypectomy was performed, and histopathology confirmed a diagnosis of benign inflammatory cap polyposis. At 3-month follow-up, sigmoidoscopy showed multiple recurrences of polyps at the site of the previous rectal polypectomy, which were removed by combined hot snare polypectomy and argon plasma coagulation. At 1-year follow-up, the patient was symptom-free and had no more episodes of bloody stool. Follow-up sigmoidoscopy showed a post-polypectomy rectal mucosal scar without recurrent polypoid lesions.

• Cap Polyposis
• Epidermal Nevus
• Hematochezia

• Anti-Inflammatory Agents, Non-Steroidal/therapeutic use
• Colonic Polyps/pathology
• Colonoscopy
• Humans
• Infant
• Male
• Mesalamine/therapeutic use
• Nevus/pathology
• Polyps/complications
• Polyps/diagnosis
• Polyps/surgery
• Rectal Diseases/complications
• Rectal Diseases/diagnosis
• Rectal Diseases/surgery
• Rectum/diagnostic imaging
• Tomography, X-Ray Computed

• Chonbuk National University Hospital

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.

• Cap polyposis
• Polyps
• Rectal bleeding
• Pediatrics
• Inflammatory bowel disease

• Adolescent
• Age Factors
• Child
• Child, Preschool
• Colonic Polyps/complications
• Colonic Polyps/pathology
• Colonic Polyps/therapy
• Colonoscopy
• Digestive System Surgical Procedures
• Female
• Gastrointestinal Agents/therapeutic use
• Gastrointestinal Hemorrhage/etiology
• Gastrointestinal Hemorrhage/pathology
• Gastrointestinal Hemorrhage/therapy
• Humans
• Male
• Polyps/complications
• Polyps/pathology
• Polyps/therapy
• Rectal Diseases/complications
• Rectal Diseases/pathology
• Rectal Diseases/therapy
• Recurrence
• Retrospective Studies
• Risk Factors
• Time Factors
• Treatment Outcome

Rectal bleeding combined with the presence of a rectal mass has been traditionally associated with the presence of malignant disease. Cap polyposis is a relatively young and still undefined rare entity which mainly involves the rectosigmoid. It is characterized by the presence of inflammatory polyps. In this case report, we present a patient who was diagnosed with a solitary cap polyp of the rectum during the investigation of a bleeding rectal mass. The patient’s age and the absence of family history were not in favor of malignancy, despite the strong initial clinical impression. After confirmation of the diagnosis, the patient underwent a snare excision and remains asymptomatic. Cap polyposis, although rare, should be suspected and, when diagnosed, should be treated according to location, number of polyps and severity of symptoms.

• Cap polyposis
• Inflammatory polyp
• Rectal mass

• 2-Pyridinylmethylsulfinylbenzimidazoles/therapeutic use
• Adult
• Amoxicillin/therapeutic use
• Anti-Bacterial Agents/therapeutic use
• Anti-Ulcer Agents/therapeutic use
• Clarithromycin/therapeutic use
• Colorectal Neoplasms/drug therapy
• Colorectal Neoplasms/microbiology
• Endoscopy, Digestive System
• Female
• Glucocorticoids/therapeutic use
• Helicobacter Infections/drug therapy
• Helicobacter pylori
• Humans
• Intestinal Polyposis/drug therapy
• Intestinal Polyposis/microbiology
• Prednisolone/therapeutic use
• Rabeprazole
• Recurrence
• Remission Induction

Cap polyposis is a rare disorder with characteristic endoscopic and histological features; its etiology is still unknown, and no specific treatment has been established. We report a case of cap polyposis that improved remarkably after infliximab infusion and had no recurrence for 3 years.

• Cap polyposis
• Infliximab
• Long term follow up
• Therapeutics

• Adenomatous Polyposis Coli/drug therapy
• Adenomatous Polyposis Coli/microbiology
• Adenomatous Polyposis Coli/therapy
• Anti-Bacterial Agents/administration & dosage
• Anti-Infective Agents/administration & dosage
• Defecation/drug effects
• Defecation/physiology
• Female
• Helicobacter Infections/microbiology
• Helicobacter Infections/physiopathology
• Helicobacter Infections/therapy
• Helicobacter pylori/drug effects
• Helicobacter pylori/isolation & purification
• Humans
• Middle Aged
• Muscle, Skeletal/microbiology
• Muscle, Skeletal/physiopathology
• Recurrence
• Remission Induction
• Sprains and Strains/microbiology
• Sprains and Strains/physiopathology

• Diagnosis, Differential
• Humans
• Intestinal Mucosa/pathology
• Rectal Prolapse/complications
• Rectal Prolapse/pathology
• Rectum/pathology
• Syndrome
• Ulcer/complications
• Ulcer/pathology