Waardenburg syndrome with isolated deficiency of myenteric ganglion cells at the sigmoid colon and rectum

Waardenburg syndrome(WS) has the characteristic clinical features caused by the embryologic abnormality of neural crestcells. WS patients sometimes suffer from functional intestinal obstruction. When it is Hirschsprung disease (HD), the WS is diagnosed as type 4 WS. We report a case of WS which did not have myenteric ganglioncells in the sigmoid colonand rectum. Whether to diagnosis this case as type 1 or 4 WS is controversial. Moreover, this is the third report which has peristalsis failure causedby abnormal myenteric plexus. In all three cases, the eosinophils had aggregated in the myenteric layer of the transition zone. During embryonic life, enteric ganglioncells migrate to the myenteric layer from the proximal to the distal side sequentially and, subsequently, to the submucosal layer through the circular muscle. Therefore, we hypothesize that myenteric ganglioncells that had already migrated were eliminated by an eosinophil-mediated mechanism in these three cases. We believe this report may be helpful to elucidate the pathogenesis of some types of HD.