Nephrocalcinosis: A Case Report

Nephrocalcinosis is characterized by increased calcium deposition within the renal parenchyma, most commonly affecting the renal medulla and less frequently the cortex, and may result in progressive renal dysfunction.It is often detected incidentally through imaging modalities such as abdominal radiography, ultrasonography, or computed tomography (CT).We report the case of an 18-yearold female with a history of recurrent nephrolithiasis and growth retardation who presented with acute left flank pain, gross hematuria, and mild dehydration.Laboratory evaluation revealed hypercalciuria, hyperchloremic metabolic acidosis with a normal anion gap, and inappropriately alkaline urine.Imaging studies demonstrated bilateral medullary nephrocalcinosis and a 17-mm calculus at the left ureteropelvic junction, resulting in grade 3 hydronephrosis.Non-contrast CT confirmed the diagnosis and excluded infectious or obstructive complications.The ureteral stone was successfully removed via ureteroscopy without complications.Based on clinical and laboratory findings, a diagnosis of distal renal tubular acidosis (dRTA) was established, and alkali therapy with sodium bicarbonate and potassium citrate was initiated.Nephrocalcinosis is frequently associated with dRTA, a disorder characterized by impaired urinary acidification leading to alkaline urine in the presence of hyperchloremic metabolic acidosis.Early recognition is crucial to prevent recurrent nephrolithiasis and long-term renal impairment.