A Rare Presentation of Bilateral Pheochromocytoma With a Flank Pain Radiating to the Back: A Case Report and Narrative Review.

Background/Objective: Pheochromocytoma is a rare catecholamine-producing tumor that often presents with episodic hypertension, headache, and sympathetic overactivity. Although bilateral adrenal involvement occurs in up to 10% of cases and flank/back pain has been reported in the literature, normotensive presentations without classic symptoms remain diagnostically challenging. Case Report: We report a 32-year-old woman with bilateral flank pain radiating to the back and no history of hypertension or classical symptoms. Imaging revealed bilateral adrenal masses; hormonal studies showed noticeable increased plasma metanephrine and normetanephrine levels. After preoperative optimization, she underwent a left robotic and right open adrenalectomy. Histopathologic and immunohistochemical analysis confirmed the diagnosis of pheochromocytomas. She was discharged with steroid replacement and remains disease-free on follow-up. Discussion: This case highlights the atypical presentation of bilateral pheochromocytomas without hypertension. The absence of classic symptoms and normal urinary catecholamines can delay diagnosis. However, increased plasma metanephrine levels and imaging findings were crucial in guiding timely surgical management. Conclusion: Clinicians should consider pheochromocytoma in patients with unexplained, persistent flank pain-even in the absence of hypertension. Early imaging and plasma metanephrine testing are essential for accurate diagnosis in such atypical cases.