Ganglion Cells Are Frequently Present in Pediatric Mucosal Colorectal Biopsies: H&E Sections and Calretinin Immunohistochemistry in the Evaluation of Children With Chronic Constipation

Abstract

Hirschsprung disease (HD) rarely presents as chronic constipation after the newborn period. At our institution, calretinin immunohistochemistry (CAL) is frequently requested by clinicians on rectal mucosal biopsies (RMBs) taken during colonoscopy in older children in whom suspicion for HD is low. We hypothesized that review of these biopsies would frequently reveal ganglion cells (GCs). We reviewed features of mucosal biopsies (November 2013 to September 2015) from children ≥1 year of age on which clinicians had requested CAL on at least one specimen. A total of 93 biopsies with paired CAL from 83 patients were suitable for study (ages 1–18 years, M:F 1.2). Submitted clinical indication was constipation in 62 patients (75%). GCs were found within or subjacent to muscularis mucosa in 63 biopsies (68%), 12 (19%) of which were designated from a specific anatomic site, eg, 2 or 3 cm. In 25 of 63 (40%) cases, GCs were identified on one of the first 3 sections (median 5th, range 1st–54th). Forty-six cases (73%) contained no or <0.5 mm of submucosa (SM, range 0–2 mm). All but one case (62/63, 98%) with identified GCs showed positive CAL staining; a single case showed equivocal staining. Among the 30 biopsies with no observed GCs, none (0%) had >1 mm of SM, and 21 (70%) had no SM. CAL was positive in 28 (93%) and equivocal/weak in 2 (7%); no additional work-up for HD was pursued. The data suggest that H&E sections of RMBs can exclude HD at a specified site in many cases and provide the basis for a future study examining the utility of CAL in RMBs without SM as a means for excluding HD.