Migration of a fish bone into the right renal vein

We describe a patient in whom a fish bone penetrated the duodenum and migrated into the right renal vein. The bone was successfully removed with surgery. The 75-year-old man was admitted to Nippon Medical School Tama Nagayama Hospital because of right upper abdominal pain persisting for 7 days. The patient's medical history was not relevant to the current disorder. Plain radiography showed no abnormalities. Computed tomography revealed a linear object of high intensity that had penetrated the duodenum and migrated into the right renal vein with thrombus. The object was surrounded by a low-density area, suggesting severe inflammation. The patient had eaten fish 1 day before the onset of abdominal pain. We diagnosed duodenal penetration caused by an ingested fish bone. Endoscopic examination showed erosion, but no fish bone or ulceration was detected in the duodenum. The patient was treated conservatively with fasting, peripheral parental nutrition, and intravenous antibiotics. Three days after admission, non-contrast-enhanced computed tomography showed no movement of the foreign body. The patient continued to have pain, and the decision was made to surgically explore the abdomen. Intraoperative ultrasonography showed that the foreign body had migrated completely into the right renal vein with thrombus. Severe inflammation of the right renal vein was observed. Because we could not remove the foreign body without seriously injuring the right renal vein, right nephrectomy was performed. Macroscopic examination of the surgical specimen confirmed the presence of a fish bone with thrombus in the right renal vein. The patient was discharged 9 days after operation, with no complications.