Calretinin immunostaining as an adjunct in the diagnosis of Hirschsprung disease

Historically, the diagnosis of Hirschsprung disease was made by evaluating multiple hematoxylin and eosin–stained slides and performing acetylcholinesterase histochemical staining. Recently, calretinin immunohistochemical staining has been reported and found to be superior to acetylcholinesterase staining in the confirmation of aganglionosis. We retrieved tissue blocks from 23 patients with proven Hirschsprung disease from the archives of the Medical College of Georgia. In addition, we selected 23 control patients with ganglion cells. All cases were stained with calretinin, and the presence or absence of both intrinsic nerve fibers (INFs) and ganglion cells was scored by 4 pathologists with fairly strong agreement (κ = 0.858). All cases of proven Hirschsprung disease were negative for INFs. Eighty-three percent of non-Hirschsprung patients were positive for INFs. Based on statistical analysis, the association between disease status and pathologist rating was statistically significant (P < .0001). We also found calretinin immunostaining to be a useful adjunctive modality in the diagnosis of Hirschsprung disease.