A near-miss: case of pseudo-foreign body in End Stage Renal Disease

Lanthanum Carbonate (LaC) is a non-calcium-based phosphate binder, widely used in patients with End-Stage Renal Disease (ESRD) for hyperphosphatemia. Due to its radio-opaque properties, LaC may appear similar to contrast agents on imaging, and typically presents as scattered calcific densities throughout the intestines. Here, we report a patient with ESRD who presented with fever, vomiting and cholestatic liver injury, worrisome for hepatobiliary sepsis. Computed Tomography (CT) scan of the abdomen incidentally noted a 1.1 cm high density object of 7000 Hounsfield units (HU) in the stomach, suspicious for an ingested metallic foreign body. Urgent surgical consult was obtained for endoscopic retrieval, but eventual clinical consensus was for conservative management as ingested LaC was considered as one of the differentials. We elegantly demonstrated gut transition of LaC on serial radiographs, and the patient was discharged well. This case report highlights a rare appearance of LaC masquerading as a metallic foreign body, which clinicians should be aware of, so as to avoid inadvertent procedures. Clinical history and serial examination are paramount to distinguish the two, failing which interval imaging might be useful as an adjunct.