A 64-year-old male had been pointed out gastric polypoid lesion since these 25years. After admission on our hospital, he was diagnosed as gastric submucosal tumor (SMT) by endoscope. Endoscopic ultrasonography revealed multiple small and large aechoic area in the third layer of the stomach wall, suggesting that the tumor was different from typical SMT like leiomyoma.
In order to define the diagnosis, polypectomy was done. Histological examination of the polypectomized specimen showed pyloric gland cavities with small and large cystic delatation in the submucosal layer and the interstitium composed of hyperplastic muscule bundle branches and the lesion was diagnosed as a hamartomatous polyp. The cystic dilatations corresponded to aechoic area on endoscopic ultrasonography and this finding was useful for the diagnosis of hamartomatous polyp.
