Neuronal intestinal dysplasia

Neuronal intestinal dysplasia (NID) is an inhibitory malformation of the submucous and myenteric plexuses. The diagnosis is made by examination of mucosal biopsies after histotopochemical reactions for acetylcholinesterase and lactate or succinate dehydrogenase. The rare NID type A is a disorder of the sympathetic nerves and usually leads to obstructive symptoms, diarrhea containing blood and mucus, and occasionally bowel perforation. Colostomy and resection of the affected bowel segment are unavoidable. Type B involves hyperplasia of the submucous plexus. The biopsy technique and criteria for evaluation have been standardized by prominent pathologists; the histochemical characteristics have been analzed morphometrically. Despite virtually uniform clinical symptoms, varying degrees of histochemical involvement may occur. Since maturation of the propulsive activity is possible in all forms, as a general rule a trial of conservative therapy should be made for at least 6 months. Persistent fecal retention with absence of internal sphincter relaxation can be treated successfully in 90% of cases by posterior sphincteromyotomy. Patients with massive rectal dilatation and absent propulsion require resection of the rectum and descending colon, as rectosigmoidectomy is associated with a high incidence of recurrence. The treatment of aganglionosis in combination with NID necessitates a differentiated work-up and set of indications.