Stevanović, Dejan (57461284600)Dejan (57461284600)StevanovićAleksić, Vuk (53871123700)Vuk (53871123700)AleksićStojanović, Dragoš (7007127826)Dragoš (7007127826)StojanovićMitrović, Nebojša (56235199600)Nebojša (56235199600)MitrovićJašarović, Damir (26023271400)Damir (26023271400)JašarovićBokun-Vukašinović, Zorana (56720406600)Zorana (56720406600)Bokun-Vukašinović2025-06-122025-06-122019https://doi.org/10.2298/SARH180312037Shttps://www.scopus.com/inward/record.uri?eid=2-s2.0-85069298167&doi=10.2298%2fSARH180312037S&partnerID=40&md5=7c9157b7a5f800f3e5b5aea24381fb74https://remedy.med.bg.ac.rs/handle/123456789/5746Introduction Osseous metaplasia is a heterotopic formation of bone and its appearance in benign gastrointestinal polyps is exceedingly rare. The mechanism responsible for this type of metaplasia is not fully understood, however it seems to be an innocent rare phenomenon. Case outline We present a case of a 31-year-old male with mesenchimal osseal metaplasia in a large inflamatory polyp measuring 57 × 23 × 20 mm in diameter, located in the anal canal region. Conclusion According to our knowledge, this is the largest gastrointestinal polyp with osseous metaplasia described so far. Although a rare phenomenon, there are certain characteristics of this disease, so we conducted a literature review and summarized these characteristics. © 2019 Serbia Medical Society. All rights reserved.Gastrointestinal polypsInflamatory polypsOsseous metaplasia