HISTOPATHOLOGICAL CRITERIA FOR INTESTINAL NEURONAL DYSPLASIA OF THE SUBMUCOSAL PLEXUS (TYPE-B)

The aim of this study was to review critically the diagnostic features of intestinal neuronal dysplasia type B (IND B). Over a period of 5 y ears colonic mucosal biopsies of 773 children with symptoms of chronic constipation were examined. Four biopsies taken 2-10 cm above the pec tinate line were cut in serial sections and histochemical lactate dehy drogenase, succinate dehydrogenase, (SDH) and acetylcholinesterase (AC hE) reactions performed. Presence of giant ganglia of the submucosal p lexus, being characterized by more than seven nerve cells, established the diagnosis of IND B. Giant ganglia were found to be age-independen t changes, while hyperplasia of the submucosal plexus, increase of ACh E activity in nerve fibres of the lamina propria and low SDH activity in nerve cells proved to be age-dependent findings which disappear dur ing the maturation of the enteric nervous system. Using these criteria IND B was diagnosed in 209 children. In 64 of these patients a combin ation of IND B and aganglionosis (Hirschsprung's disease) was found. I ND B seems to be related to premature expression of laminin A during e mbryogenesis, resulting in premature nerve cell differentiation in the myenteric and submucosal plexus, which in turn blocks neuroblast colo nization of the rectum. IND B, hypoganglionosis and aganglionosis, whi ch are often combined, may therefore be considered to be different man ifestations of the same developmental abnormality.