Spectrum of Clinicopathological Deviations in Long-Segment Hirschsprung Disease Compared With Short-Segment Hirschsprung Disease: A Single-Institution Study.

Hirschsprung disease (HSCR) is a congenital disorder characterized by intestinal aganglionosis leading to pseudoobstruction. The majority of cases are limited to the rectum or rectosigmoid (S-HSCR). A variably longer segment can be affected (L-HSCR), which may show many deviations from S-HSCR. We retrospectively reviewed 48 clinicopathologically confirmed total cases of HSCR at a single institution in a 21-year period to identify L-HSCR cases and determine their deviations from known features of S-HSCR. Eight L-HSCR cases were found where aganglionosis extended to the terminal ileum (7/8) or to the splenic flexure (1/8). L-HSCR lacked male preponderance and was in contrast more common in females (6/8). Associated anomalies included congenital heart disease (2) and neonatal hypothyroidism (1), previously underreported associations. The clinical diagnosis of L-HSCR was often delayed (average age at diagnosis 13 days) and the diagnosis was more often made operatively (5/8) rather than on rectal suction biopsy (3/8). Histologically, apart from aganglionosis, neural hyperplasia was either absent or focal, compounding the diagnostic difficulty. Although the number of cases in our study was limited due to the rarity of L-HSCR, this study still highlights the spectrum of deviations of L-HSCR from known clinicopathological features of S-HSCR.