Zonal aganglionosis. An enzyme and immunohistochemical study of two cases.

The existence of zonal aganglionosis, a rare variant of Hirschsprung's disease, is often questioned. An extensive enzyme and immunohistochemical study was performed on gut specimens of two patients presenting with bilious vomiting and abdominal distension to find evidence of the existence of double zonal aganglionosis and to characterize the abnormalities of the enteric nervous system. The hypotheses concerning the pathogenesis of this neurogenic disorder are reviewed. The results of our study confirm the existence of zonal aganglionosis. The clinical presentation may be similar to classical Hirschsprung's disease.