Background/Objective: Interstitial cells of Cajal (ICC) are c-kit positive immunoreactive cells which are thought to play an important role in the control of gut motility. The work aimed at studying the morphology of ICC and   precisely localize  their regional and transmural pattern of distribution in  normal human alimentary tract.
Material and Methods: The study included 102 normal human alimentary tract specimens obtained from male patients with a mean age 37.92±8.53. All sections were stained with hematoxylin and eosin and c-kit immunohistochemical staining. Immunohistochemically stained sections were submitted for a computer aided image analytical study to detect the area percent of immunoreactive cells. The data obtained was statistically analyzed.
Results: ICC could not be demonstrated in H&E stained sections.  Immunohistochemically, two morphological subtypes of ICC were recognized, a spindle bipolar and stellate multipolar forms.  ICC were detected in the myenteric plexus layer of the esophagus, corpus, pylorus, small intestine, colon and rectum.  Intramuscular ICC could be demonstrated in the esophagus, fundus, corpus, pylorus, colon, rectum and anal canal.  ICC at the deep muscular plexus were found only in the small intestine.  In the pylorus, colon and rectum, ICC were also found at the submucosal border of the circular muscle layer.
Conclusion: The wide distribution of ICC all over the human alimentary tract is compatible with their physiological role being important mediators of gut motility.