Abstract
Objective : We investigated the distribution of neuroendocrine (NE) cells in rectal and large bowel mucosa from patients with isolated intestinal neuronal dysplasia (IND group) and Hirschsprung's Disease (HD) complicated by IND (HD/IND group) to improve understanding of the etiology of IND.
Materials : Rectal biopsy specimens from eight patients with IND (mean age : 5.4+2.3 years, 4 male, 4 female) and resected surgical specimens from seven patients with HD/IND (mean age : 3.5+2.9 years, 4 male, 3 female) treated in our unit between 1 January 1995 and 31 December 2001 were the subjects of this study. Twenty patients who underwent bowel resection for conditions unrelated to bowel motility disorders acted as controls.
Methods : Immunohistochemistry using avidine-biotinilated complex and monoclonal antibodies to chromogranine A (ChA) and serotonin (5HT) were used to compare the distribution of NE cells in bowel specimens. HD/IND specimens were further subdivided into aganglionic, transitional, and IND segments. NE cells were counted under light microscopy. Tests for significant differences between groups were performed using Student's t-test.
Results : ChA immunoreactive cells were increased in IND (3.35+0.56) compared with controls (0.87+0.26) (p<0.01). 5HT immunoreactive cells were also increased in IND (2.78+ 0.29) compared with controls (0.25+0.05) (p <0.01). There was an increase in the number of ChA and 5HT immunoreactive cells in both aganglionic (ChA : 3.25+0.28, 5HT : 2.78+.34 and transitional (ChA : 2.67+0.32, 5HT : 2.01+0.24) segments of HD/IND compared with controls (p<0.01). Interestingly, immunostaining for ChA (5.23+1.25) and 5HT (4.23+0.56) in IND segments of HD/IND was significantly higher than in the aganglionic segment (p<0.05).
Conclusion : There was a consistent increase in mucosal NE cells in segments of bowel with typical histopathologic features of IND. The results suggest that an increase in mucosal NE cells may cause abnormal neuronal histopathology such as giant ganglia and hyperganglionosis and play a role in regulating contraction of the intestine in IND.
