Features of Hirschsprung's disease:
(1) absence of ganglion cells (aganglionosis)
(2) nerve hypertrophy
(3) abnormal acetylcholinesterase staining (very specific but not as sensitive)
(4) negative immunostain for calretinin
Problems associated with a suction rectal biopsy:
(1) a biopsy taken too close to the pectinate line (dentate line), due to the physiologic paucity of ganglion cells
(2) a superficial biopsy without sufficient submucosa
(3) difficulty identifying ganglion cells, especially in neonates
Standard histologic examination of a rectal biopsy may involve examination of 100 or more sections in order to confidently demonstrate aganglionosis. This type of examination can be expensive.
Calretinin is considered superior to acetylcholinesterase for detection of Hirschsprung's disease, since the test can be done more reliably and because the test is both sensitive and specific.
Exclusion of Hirschsprung's disease - either of the following:
(1) demonstration of ganglion cells
(2) calretinin positivity in the submucosa, muscularis mucosae or lamina propria
