Anorectal Malformation Fistula Evaluation May Aid in Hirschsprung Diagnosis

Concurrence of Hirschsprung disease (HD) and anorectal malformation (ARM) is rare, but early diagnosis is important for proper management. The aim of this study was to define the expected histological findings of rectal fistulae in ARM and to identify findings that may raise suspicion for concurrent HD.

Eighty-six patients with ARM from a single institution were studied. Pathology reports as well as randomly selected fistula specimens were evaluated for the presence of ganglion cells at a single institution. An additional query of the Pediatric Colorectal and Pelvic Learning Consortium database was performed to examine clinical features of patients with HD and ARM.

Patients represented the spectrum of ARM, with perineal fistula being the most common. Ganglion cells were present in 78 of 86 (91%) specimens, hypoganglionosis in 5 of 86 specimens (6%), and absent in 3 of 86 (4%) specimens. Of the patients with absence of ganglion cells in their fistula specimens, 2 of 3 (66%) also carried a diagnosis of Trisomy 21. Within the Pediatric Colorectal and Pelvic Learning Consortium database, we identified 12 patients with both ARM and HD out of 1726 ARM subjects (0.7% of ARM patients). Among this group of patients, 33% (n = 4) had chromosomal anomalies.

The majority of fistula specimens from patients with ARMs contain ganglion cells. Absence of ganglion cells in patients with ARM should prompt suspicion for HD. This association may be more common in patients with chromosomal anomalies.