Juvenile Retention Polyps

A previously healthy 3-year-old girl presented to the emergency department (ED) with a 2-day history of bloody stools and abdominal pain. The first of 4 episodes had featured bright red blood from the rectum and had been associated with cramping abdominal pain. Subsequent episodes had been painless and had involved loosely formed stool covered with bright red blood.

The patient had had no fever, vomiting, dizziness, or headache. Her pediatrician had seen her the day before presentation to the ED and had prescribed trimethoprim-sulfamethoxazole, of which she had taken one dose.

On initial physical examination, the girl was pale with a temperature of 37°C, heart rate of 112 beats/min, respiratory rate of 24 breaths/min, and blood pressure of 80/63 mm Hg. No abdominal tenderness, hepatosplenomegaly, lymphadenopathy, anal fissures, or external hemorrhoids were appreciated. She was admitted for further workup.

Laboratory test results showed microcytic anemia (hemoglobin, 7.2 g/dL; mean corpuscular volume, 55 µm³), thrombocytosis (platelet count, 539 × 10³/µL) and a low reticulocyte count (1.3% of red blood cells). The serum iron level (16 µg/dL), transferrin saturation (4%), and ferritin level (3 ng/mL) were decreased. A fecal occult blood test was positive. Results of stool viral and bacterial studies were negative. She was started on iron supplementation.

Results of a technetium-99m pertechnetate scan were negative for a Meckel diverticulum. A colonoscopy was then performed and revealed 6 polyps ranging in size from less than 1 cm to approximately 3 cm in diameter. They were located in the ascending, transverse, descending, and proximal colon. All polyps were removed via polypectomy, and pathology results were consistent with juvenile retention polyps. The patient remained clinically stable throughout her hospitalization. She continued on iron supplementation therapy and was discharged home after 5 days.

Colonic polyps are common in children and most frequently present with painless rectal bleeding. They also may present with a prolapsing rectal mass or mucopurulent stools, the latter of which were experienced by our patient. Approximately 75% to 90% of childhood polyps are classified as juvenile polyps. They also are known as inflammatory polyps, retention polyps, and hamartomatous polyps depending on their predominant histology, which features distinctive cystic architecture, mucus-filled glands, and infiltration by inflammatory cells. The term juvenile refers to the polyp’s type, not the age of onset.

Juvenile polyps most frequently are diagnosed before the age of 10 years, with the peak age of diagnosis between 2 and 5 years of age.¹ Their etiology remains unknown; one hypothesis is that these polyps are a form of allergic inflammation of the colonic mucosa.²

Juvenile polyps usually are from 1 cm to 3 cm in size, solitary, rectosigmoid, and pedunculated. Isolated juvenile polyps do not carry a risk of intestinal cancer, but approximately 50% of children with juvenile polyps have more than one polyp. The number of polyps is important, because patients with more than 5 might have juvenile polyposis syndrome, an autosomal dominant condition that carries a 50% risk of developing gastrointestinal cancers, including colorectal and gastric carcinomas.³ For isolated juvenile polyps, colonoscopy with polypectomy and histologic review is the preferred management approach.

The differential diagnosis for rectal bleeding is quite broad (Table).^4,5 Our case highlights a common presentation of juvenile polyps and a stepwise approach to the correct diagnosis.

References

1. Durno C. Colonic polyps in children and adolescents. Can J Gastroenterol. 2007;21(4):233-239.

2. Roma-Giannikou E, Papazoglou TA, Panayiotou JV, et al. Colon polyps in childhood: increased mucosal eosinophilia in juvenile polyps. Ann Gastroenterol. 2008;21(4):229-232.

3. Howe JR, Mitros FA, Summers RW. The risk of gastrointestinal carcinoma in familial juvenile polyposis. Ann Surg Oncol. 1998;5(8):751-756.

4. Silber G. Lower gastrointestinal bleeding. Pediatr Rev. 1990;12(3):85-93.

5. Teach SJ, Fleisher GR. Rectal bleeding in the pediatric emergency department. Ann Emerg Med. 1994;23(6):1252-1258.