What are the diagnostic criteria for intestinal neuronal dysplasia?

The incidence of isolated intestinal neuronal dysplasia (IND) has varied from 0.3% to 62% of all suction rectal biopsies in different centres. The uncertainty regarding the incidence has resulted from the considerable confusion regarding the essential diagnostic criteria. In an attempt to clarify the diagnostic criteria for IND, we examined biopsy material from the following three groups using acetylcholinesterase (AChE) histochemistry: (1) full-thickness normal colon from 23 controls; (2) suction rectal biopsies from 9 patients who had isolated IND; and (3) full-thickness biopsies from 10 patients with Hirschsprung's disease (HD) who demonstrated IND in the proximal margin of the resected segment. Our data show that hyperganglionosis is the most consistent finding in both IND associated with HD and isolated IND. Other histochemical criteria of IND were dependent upon whether the biopsy was full-thickness or a suction rectal biopsy. Where full-thickness biopsies were available, giant ganglia and ectopic ganglion cells were seen in all cases. Increases in AChE-positive nerve fibres in the mucosa was a frequent finding in patients with IND diagnosed by suction rectal biopsies. We recommend that patients suspected to have IND on suction rectal biopsy should have a full-thickness biopsy for detailed examination of the submucous and myenteric plexuses.