Calretinin is a ‘calcium-binding protein that is normally expressed in cholinergic nerves.’ (NEJM 2012:366: 361-72)  The absence of calretinin-positive mucosal neurites helps establish a diagnosis of Hirschsprung’s disease, even when suction-biopsy specimens may have previously been considered inadequate.  It is not known why calretinin neurites are absent in Hirschsprung’s disease nor why abnormal acetylcholinesterase-positive neurites are present.

More information on the technical aspects of diagnosing Hirschsprung’s disease and illustrations of these stains is available in this case record.

Additional references:

• -Mod Pathol 2009; 22: 1379-84. Calretinin in Hirschsprung’s.
• -Pediatr Dev Pathol 2009; 12: 6-15. Calretinin & acetylcholinesterase in Hirschsprung’s.
• -JPGN 2011; 53: 75.  Problems post-op.
• -JPGN 2008; 46:13.  Nice review.
• -Pediatrics 2002; 109: 914-918.  Review of surgical treatments.
• http://www.ccdhc.org/diseases/Hirschsprung.html