Dysmorphic Neurofilament-Positive Ganglion Cells in the Myenteric Plexus at the Proximal Resection Margin Indicate Worse Postoperative Prognosis in Hirschsprung's Disease

Background Hirschsprung's disease (HD) is a congenital disorder affecting neonates that presents with distal intestinal obstruction. It is the most common type of anorectal malformation. Treatment of HD consists of surgical removal of the distal colon including the most distal aganglionic segment, the transitional zone, and a prudent length of proximal colon that is determined during the surgical procedure to be normally ganglionated by intraoperative demonstration of normal ganglion cells up to and including the surgical resection margin. Methods In a retrospective study of formalin-fixed paraffin-embedded colon tissue from the proximal resection margin (PRM) of 209 HD patients, we made morphometric measures and detected immature ganglion cells defined as dysmorphic by immunohistochemical demonstration of cytoplasmic neurofilament (NF). Results The majority of NF-positive ganglion cells in HD patients appeared immature, with less cytoplasm. Occasional positive ganglion cells in the same patients appeared mature with abundant eosinophilic cytoplasm, Nissl bodies, prominent nucleoli, and adjacent glial cells. Patients with NF-positive ganglion cells in the myenteric plexuses at the PRM may have poor postoperative recovery. Conclusion We propose that NF expression in dysmorphic ganglion cells at the PRM may predict poor outcome after pull-through surgery for HD.