Reno-Duodenal Fistula Caused by Metastatic Lung Cancer.

Reno-duodenal fistulas are an extremely rare complication of radiotherapy in patients with metastatic lung cancer. Here we describe the case of a 60-year-old man with metastatic non-small cell lung cancer treated with chemoradiation who presented with fever, chills, and flank pain and was found to have septic shock with polymicrobial bacteremia and fungemia. Subsequent imaging showed evidence of a reno-duodenal fistula. After a failed attempt at endoscopic closure, the patient was not deemed a surgical candidate due to poor performance status and advanced metastatic disease and was transitioned to home hospice care. This report highlights the importance of considering reno-alimentary fistulization in the differential diagnosis of emphysematous pyelonephritis, especially in the setting of radiation therapy and malignancy.