New classification of histochemical staining patterns of acetylcholinesterase activity in rectal suction biopsy in Hirschsprung's disease.

Several previous studies have introduced classifications of Acetylcholinesterase (AChE) histochemical staining patterns in rectal suction biopsy performed in patients with Hirschsprung's disease. However, we introduce a new classification that is less complicated but shows the same age dependence as seen in previous studies. 135 rectal suction biopsies were submitted to histochemical staining for AChE activity and 88 specimens showed increased AChE activity. Therefore, we retrospectively analysed these 88 cases and could establish three patterns. Pattern I, presence of thick nerve trunks or coarse nerve fibers only in the muscularis mucosae and submucosa. This pattern was mainly seen in children aged 6 months or below. Pattern II, presence of abundant nerve fibers in all three layers of mucosa. This pattern was predominantly seen in children over 6 months of age. Pattern III, not predominant in any age group, showed positive nerve fibers in all three layers but, in one or more layers, the nerve fibers were sparse. Upon comparison with previous studies, we could observe the same age-pattern relationship. Thus, we propose this method of classification as a new tool to classify AChE histochemical staining patterns.