Inflatntnatory fibroid polyp causing colocolic intussusception in an infant

M WALTON, J BASS, B CARPENTER. Inflammatory fibroid polyp causing colocolic intussusception in an infant. Can J Gastroenterol 1994;8(4 ):246248. A three-month-olc.l infant presented to the emergency department with a 24 h history of irritability and lesion prolapsing intermittently per anus. The child had a six-week history of blood and mucL1s per rectum. Digital rectal examination and sigmoidoscopy revealed what appeared to be a large mobile polypoid lesion arising from the rectum. Plans for excision were made. S igmoidoscopy performed the following morning failed to demonstrate any lesion in the rectum or sigmoid. Barium enema demonstrated a sessile 'apple core type' lesion in the descending colon. Segmental resection of the descenc.ling colon with end-to-end anastomosis was performed. Pathological examination of the resected bowel demonstrated features consistent with an inflammatory fibroid polyp. This case appears to be unique because of the young age of the patient, its unusual location and its presentation as an intermittent colocolic intussusception.

Most ca:,es reported h ave been 111 the adult population.We report a case of an inflammatory fibroid polyp presenting 111 a three-mo nth-old infant.

CASE PRESENTATION
A three-mllnth-old male presented to the eme rgency departme nt with a 24 h history of irri tability a nd interm lt• tent pmlapse uf a lesion per anus.The c hilc.l hnd a six-week history of blood and mucus per rectum.A le~ion prolapsing intermittently per anus was seen.Digital rectal examination n:veakd what appea red to be a large mobile pnlypoid lesion.A rigid sigmrndoscopy was performed 111 the emergen cy department demomt rating a friahle le~ion in the rectum.The initial impression was that this polypoid lesion was arising from the rectum.Plan for removal of the polyp under general anesthesia the next morning was arranged.S igmoidoscnpy performed the follow111g morn111g failed to de mon-mate any lesio n in the rectum or sig-moi<l.
Barium enema was then performeJ, demonstrating a sess ile 'apple core type' bion in the Jescen<ling colon (Figure I).It was clear that probably the a ir introduced <luring the sigmoidoscopy the previous night ha<l reduced the howel to its normal position.After mechanical bowel preparation, the patien t un<lerwem segmental resection of the JescenJing colon with end-to-end anastomosis.Pathological examination of the resccte<l bowel demonstrated features consistent with an inflammatory fibroi<l polyp (Figure 2) .Fourteen month~ posroperatively rhe child remains asymptomatic.

DISCUSSION
Inflammatory fibroid polyp is a rare hcnign lesion seen mostly in adults, generally occu rring in the gastroduodenal area and small bowel.1:-listologically it i~ characterized by a fibrous polypoid lesion originating in the submucosa extending through the muscu-

Colocolic intussusception
Figure 2) Representative section from colonic />aly/i shows ihe cliarac-Lerisric fibroblasiic srroma wirh fascicles and iuhorls of proliferating fibroblasts, arbori:dng vessels and randomly distrihmed inflammawry celL~, inclwling eosinophils ( tric/1rome x86) Figure 1) Left Barium enema: 'apple core r.ype' lesion in the descending colon laris mucosae into the mucosa.It contains abundant inflammatory cells including eosinophils in various amounts.Associated mucosa!ulceration is frequent.Although once believed to be associated with eosinophilic gastroenteritis (7,8), it represents a sepa rate e ntity of unknown etio logy (6,9,10).Peripheral blood shows no eosinophilia ( I I).Almost all lesions are focally ul-cerateJ, likely secondary LO the intraluminal location and incussusception of the polyp ( 12).The stroma contains concentrically arranged fibroblast and is infiltrated by eosinophils to a varying degree, often to a great extent.Occasiona l mitoses are found; however, there is no acypia.
There is inflammatory granulation tissue infi ltrating rhe submucosa and mucosa at the marg in of the polyp.Granulomas per se a re nor a component of inflammatory fibroiJ polyps.The granu lat ion tissue on the floor of the ulcer is often invasive as in nodular fasc iitis.There is a striking similarity in light microscopy and ulrrastructural features, as well as biological behaviour between inflammatory fib roid polyps and some types of fibromatosis (13).lmmunohiscochemical study in some cases suggests a myofibroblastic origin for the proliferating cells ( I 3, 14 ).
Adults, mean age of 48 years, form the majority of pacients described in the literature (12).We could find only I 2 cases of inflammatory fibroid polyp in children reported in the literature (I 0, I 2, 15-20).In six patients, it was located in the esophagus, ileum, jejunum, transverse colon and recwm, and in the remaining seven patients, the site was nor specified.The youngest patient previously repo rted was two years old.We could not find any report of inflammmory fibroid polyp in children in the gascroduodenal area, the most common location in the adult population.
The polyp is obstructive ( 15) and presenting symptoms de pend on the location of the lesion.Nonspecific symptoms include abdominal pain, vomiting, abdomina l distension, gastro-intestinal bleeding and weight loss.Intussusception is almost always the presenting feature for lesions located in the sma ll bowel (1 2).Duration of symptoms as long as 20 mo nths has been described.However, 76% of the patients have symptoms for four weeks or less (12).
Recurrence has o nly been reported in an ileal lesion in a two-year-old child (18).Treatment is t hat of local resection a nd che prognosis is good.