Rectal mucosal biopsy in aganglionosis and allied conditions.

Rectal mucosal biopsies were performed in 146 patients suspected of having Hirschsprung's disease. The biopsies were serially sectioned and screened for the presence of ganglion cells. In the 101 cases in which ganglion cells were found, the diagnosis of Hirschsprung's disease was ruled out. In 45 patients, histologic examination revealed the typical features of Hirschsprung's disease, i.e., the absence of ganglion cells and the presence of numerous hypertrophied nerve bundles. The varied morphologic features of Meissner's plexus in patients of different ages and the diagnostic pitfalls are described in detail. Serial frozen sections stained with hematoxylin-eosin were examined in eight cases of neonatal intestinal obstruction and enterocolitis. This method was found to be useful and reliable in emergencies. In three of these cases ganglion cells were found and major surgical procedures were avoided. In 73 cases, staining for acetylcholinesterase activity was performed. The results matched the microscopic findings in all but three false-positive cases.