Delayed maturation of interstitial cells of Cajal in meconium obstruction.

BACKGROUND/PURPOSE The etiology of meconium obstruction without cystic fibrosis is unclear. Interstitial cells of Cajal (ICC) function as pacemakers in gut motility and may play a role in the pathophysiology of the disease. METHODS The ICC were examined by immunohistochemical staining with anti-c-kit antibody in the bowel walls of 6 neonates who had meconium obstruction without cystic fibrosis, and the results were compared with specimens from normal neonates (n = 2). RESULTS Six patients underwent ileostomy between 2 and 15 days after birth, and 5 of them presented with microcolon. Ganglion cells were present in the ileum and colon. Whereas ICC were evenly distributed in the control specimens, they were not seen at the time of ileostomy in the colons of 2 patients, and the other 4 showed scanty distribution in muscle layers. However, ileum showed normal distribution of ICC in all patients. The ileostomies were closed between 39 and 104 days of age, and the ICC distribution was changed to a normal pattern in the colons of all 6 patients. Their bowel movements were restored to normal after closure. CONCLUSION The findings of this study suggest that delayed maturity of ICC may be a cause of meconium obstruction without cystic fibrosis.