Hypoganglionosis.

Between 1973 and 1988, 280 patients suspected of having Hirschsprung's disease were examined by rectal mucosal biopsies prepared by acetylcholinesterase (AChE) and hematoxylin-eosin staining. Twelve of these patients were histologically diagnosed as having hypoganglionosis; rectal mucosal biopsies in all 12 showed the presence of a few small ganglia. Cases of hypoganglionosis were divided into three groups based on the findings of AChE-positive nerve fibers: type A: rectal suction biopsies taken in the neonatal period showed proliferation of AChE-positive nerve fibers similar to those seen in aganglionic bowel; type B: AChE-positive nerves were virtually absent from the lamina propria in the neonatal period, but during or after infancy there was moderate to severe proliferation of AChE-positive fibers in the lamina propria; type C: rectal mucosal biopsies performed even after infancy showed no proliferation of AChE-positive fibers in the lamina propria. An accurate diagnosis of type C can only be made by examination of the myenteric plexus in a full-thickness rectal biopsy specimen. On barium examination, definite caliber changes were seen in 7 cases, equivocal changes in 4 and none were seen in 1. Anorectal manometry showed an atypical rectosphincteric reflex in 5 cases and absent reflex in 7. Treatment depends on the degree of clinical symptoms and length of the involved segment of bowel and consists of a definitive pull-through operation or internal sphincter myectomy [2, 3]. [ABSTRACT FROM AUTHOR]