Flank pain and hematuria is not always a kidney stone

BackgroundPatients with flank pain and hematuria are common emergency department presentations of nephrolithiasis. We may anchor on this etiology and potentially miss other less common differentials. We present a case of a patient with hematuria and flank pain typical of nephrolithiasis who was diagnosed with a Page kidney causing secondary hypertension.A 50 year-old male with no significant past medical history presented to the Emergency Department with severe left-sided flank pain, vomiting, and blood-tinged urine. We pursued a diagnosis of nephrolithiasis and found a left renal subcapsular hematoma on non-contrast CT. A CTA was done with no active hemorrhage found. The patient had no history of recent trauma and was found to be hypertensive on evaluation. Urology was consulted and management for the patient's hypertension was initiated. He was diagnosed with Page Kidney and admitted to medicine for observation and hypertension management with an angiotensin-converting enzyme inhibitor.Page Kidney is a diagnosis that describes compression of the renal parenchyma by a hematoma or mass causing secondary hypertension through the activation of the renin-angiotensin-aldosterone system. Causes may include traumatic subcapsular hematoma, renal cyst rupture, tumor, hemorrhage, arteriovenous malformation, among others. Treatment may involve conservative measures including hypertension management, or more invasive measures like evacuation or nephrectomy. We describe the case of a patient presumed to have nephrolithiasis presenting with typical left-sided flank pain, diagnosed with Page kidney, and treated conservatively.