A 70-year-old male with a history of diabetes and chronic renal disease presents with persistent fever and flank pain. He also reports night sweats and weight loss. On examination, he has tenderness over his right flank. He immigrated from a country with high TB prevalence a few years ago. What are the potential causes, and what are the next steps?
While this patient's symptoms and exam findings could be due to a urinary tract infection or pyelonephritis, his persistent fever, weight loss, and night sweats, combined with his epidemiological background, raise the possibility of renal or genitourinary tuberculosis. The next steps would be to perform urinalysis and urine culture, and also consider a urine culture for mycobacteria. Imaging of the kidneys and urinary tract, such as ultrasound or CT scan, would also be useful.