Immunohistochemistry reveals an increased number of ganglion cells in the normal-size plexus, as a pathological feature of immaturity of ganglia

Immaturity of ganglia (IG), is a rare entity of an allied disorder of Hirschsprung’s disease. We reviewed our IG cases to provide further pathological insight into IG. The clinical data and pathological findings of IG cases in our department from 2011 to 2020 were examined. Hematoxylin and eosin (HE) staining and immunostaining for HuC/D, BCL-2, SOX10, and CD56 were performed on full-thickness specimens. Sufficient clinical data and pathological specimens were available in five cases during the study period. The patient profiles were as follows: four term infants and one preterm infant with initial symptoms of abdominal distension or vomiting; all cases underwent ileostomy at a median age of 2 days and stoma closure at a median age of 5 months. Although the interpretation of HE staining was difficult, immunostaining for HuC/D and SOX10 clearly distinguished ganglion cells from glial cells. The number of ganglion cells in the IG group was significantly greater than that in the control group (p < 0.05), while the number of enteric glial cells and total area of the myenteric nerve plexus did not differ. The finding of the increased number of ganglion cells in a normal-size myenteric plexus is a novel feature of IG that contributes to its accurate diagnosis.