Bowel lanthanum deposition in an elderly patient

A 72-year-old woman visited our clinic with a chief complaint of intermittent abdominal bloating for 1 year. Her medical history included end-stage renal disease needing thrice-weekly hemodialysis since March 5, 2018, as well as a diagnosis of hypertension, which she managed with regular nebivolol, azilsartan, and hydralazine therapy. She has taken lanthanum carbonate 750 mg thrice daily for hyperphosphatemia since December 1, 2020. Physical examination revealed normoactive bowel sounds, a soft abdomen, and no abdominal tenderness. Abdominal x-ray imaging revealed numerous radiopaque densities in the small intestine and colon even though she had never received intestinal contrast medium (Figure 1). After discontinuation of lanthanum carbonate for 1 week, these radiopaque densities were all resolved (Figure 2). These numerous radiopaque densities have an important impact on image interpretation.1, 2 The differential diagnosis of multiple radiopaque densities encompasses various factors, including medication intake (such as iron tablets and phenothiazines), exposure to toxins (such as heavy metals), presence of foreign bodies, stones, and calcifications associated with conditions like chronic pancreatitis.3, 4 The history of taking lanthanum is crucial for differential diagnosis. Alternative phosphate binders may be used if such examinations are planned. From our case, we can learn how long these radiopaque densities would resolve and remind a guide for clinical physicians to arrange examinations such as barium tests. I declare that I have participated in the preparation of the article “Bowel lanthanum deposition in an elderly patient.” Ying-Chi Chiang wrote this article. Chi-Yu Lee and Ming-Jen Chen conducted the literature review. Chen-Wang Chang supported this work by performing a critical reading of the manuscript and supervising the final editing. All authors read and approved the final manuscript. The authors declare no conflicts of interest. All study participants provided informed consent, and the study design was approved by the appropriate ethics review board.