Tungtrongchitr N.Krisem M.Wicharit L.Suppadungsuk S.Thammavaranucupt K.Mahidol University2026-02-212026-02-212026-02-07Journal of Radiology Case Reports Vol.20 No.2 (2026) , 1-5https://repository.li.mahidol.ac.th/handle/123456789/115182Lanthanum carbonate is a phosphate binder in the form of a chewable tablet commonly prescribed in chronic kidney disease patients. We reported an unusual radio-opaque foreign body accidentally found in a chest X-ray of a coronavirus disease 2019 pneumonia patient. Due to awareness of mimicking other conditions (e.g., button battery or coin ingestion), an urgent endoscopy was performed. An intact lanthanum carbonate tablet was found in the upper stomach and was removed successfully. Physicians should be aware of unchewed lanthanum carbonate tablets when a metallic-like object is detected on the chest radiograph of a lanthanum carbonate user.MedicineA Round-Shaped, Radio-Opaque Foreign Body on Chest Radiograph, Identified as an Intact Lanthanum Carbonate TabletArticleSCOPUS10.3941/jrcr.59842-s2.0-10502991687619430922