Abstract
BACKGROUND: Renal tubular acidosis is a rare disorder affecting acid-base balance, and its coexistence with endocrine abnormalities such as hyperparathyroidism and pheochromocytoma is exceptionally uncommon. This combination presents unique diagnostic and therapeutic challenges requiring a multidisciplinary approach. CASE PRESENTATION: A 25-year-old Iranian woman presented with recurrent flank pain, episodic palpitations, headaches, and intermittent hypertension. Imaging revealed bilateral nephrolithiasis, leading to ureteroscopic lithotripsy. Biochemical evaluation confirmed distal renal tubular acidosis (type 1), hyperparathyroidism, and pheochromocytoma, a rare and complex association. Metabolic acidosis, hypokalemia, and elevated catecholamine metabolites were noted. Potassium citrate was prescribed for stone prevention, and the patient remains asymptomatic after a year of follow-up. CONCLUSION: This case underscores the need for heightened clinical suspicion when nephrolithiasis is accompanied by systemic symptoms. The rare coexistence of renal tubular acidosis, hyperparathyroidism, and pheochromocytoma highlights the importance of early recognition and a multidisciplinary approach to prevent complications and optimize patient outcomes.