Background: There are occasional reports of osseous metaplasia (OM) occurring in gastrointestinal polyps. We report 4 cases occurring in juvenile retention polyps. Case reports: Four juvenile retention polyps presented with rectal bleeding. Microscopically there was osseous metaplasia in addition to the typical surface ulceration and granulation tissue appearance. Discussion/conclusion: Osseous metaplasia was only detected on histopathologic examination of the resected polyps. Although the clinical significance is not established, OM suggests that the polyps have been present for a longer period of time.
Keywords: Juvenile polyps; case series; histopathology; osseous metaplasia.