A case of gross hematuria with flank pain in a 16-year-old boy: Questions

Excerpt

A 16-year-old Caucasian boy presented with intermittent gross hematuria for 3 months and an episode of bilateral flank pain 2 weeks before the clinic visit. He had no history of trauma, dysuria, frequency, urinary tract infections or passage of kidney stones. Initial workup showed normal serum creatinine of 0.7 mg/dL, normal complete blood count, normal C3, negative antinuclear antibody (ANA), and negative urine culture. Urine analysis showed 1+ blood with 51–100 red blood cells (RBC)/hpf, no RBC casts, crystals or protein. Urine calcium/Cr ratio was 0.19 mg/mg and urine protein/Cr ratio 0.14 mg/mg. Doppler renal ultrasound (RUS) performed at a local hospital showed normal renal artery blood flow. The right and left kidneys measured 11.1 cm and 11.2 cm respectively and there was no evidence of mass, hydronephrosis or stones, and the bladder was normal. …