Histochemical confirmation of the acetylcholinesterase-activity in rectal suction biopsy from neonates with Hirschsprung's disease.

Proliferating patterns of acetylcholinesterase (AChE) positive nerve fibres were investigated in 23 neonates with Hirschsprung's disease. All subjects were separated into three groups, according to age. In group A (0-10 days old) adn groups B (11-20 days old, no increase in AChE positive nerve fibres was evidenced in the lamina propria mucosae, whereas 7 out of 9 cases in group C (21-28 days old) showed a moderate or marked increase in AChE positive nerve fibres in the lamina propria mucosae. A typical pattern of this proliferation up to the lamina propria mucosae was seen in 30.4% only of all cases in the series, and was limited to group C, where the positive AChE reaction from the submucosa to the muscularis mucosae (including the submucosa only), the rate was 91.3%. Re-examination was preformed in 14 cases over sthe neonatal period. All showed a positive AChE reaction up to the lamina propria mucosae. Suction biopsy specimen from neonates is sometimes inadequate with respect to the lack of inclusion of the muscularis mucosae and submucosa, as a result of a weakly negative pressure by suction. The normal reactions of AChE activity in the lamina propria mucosae do not exclude Hirschsprung's disease in neonates. Therefore, when a histochemical diagnosis of Hirschsprung's disease using rectal suction biopsy for staining of AChE activity is required in the neonatal period, the diagnosis is safe and relatively easy at least over three weeks of age as mentioned above.