Zonal colonic aganglionosis, a variant of Hirschsprung's disease.

On a review of 15 cases of Hirschsprung's disease of the colon we have encountered 4 cases of an atypical variant. These 4 cases had a zone of aganglionosis of both intermyenteric and submucous plexuses in the sigmoid colon and, in 1 case, a further zone of aganglionosis in the rectum. Ganglion cells reappeared distal to the sigmoid zone of aganglionosis. A transition zone was not invariably present. The clinical features demonstrated a variability of presentation typical of the more usual form of the disease. The importance of atypical Hirschsprung's disease is discussed from a diagnostic and pathogenetic viewpoint.