Acute Kidney Injury and Nephrotic-Range Proteinuria as Initial Presentation of Pheochromocytoma: A Case Report.

Introduction: Pheochromocytomas are rare catecholamine-producing neuroendocrine tumors that present with the classical triad of paroxysmal hypertension, palpitations, and sweating; however, this presentation is seen in less than 1/4 of pheochromocytoma patients. Hypertension is usually the predominant manifestation. Atypical manifestations, including renal involvement, are infrequent and may delay diagnosis. Case Presentation: We report the case of a 37-year-old male with no prior comorbidities who presented with progressive abdominal pain, shortness of breath, and oliguria. Laboratory evaluation demonstrated acute kidney injury with nephrotic-range proteinuria, initially raising suspicion of a primary glomerular disorder. Chest imaging revealed pulmonary congestion, while abdominal imaging identified a right adrenal mass. Plasma-free metanephrine and normetanephrine levels were markedly elevated, confirming pheochromocytoma. The patient underwent preoperative optimization with alpha-adrenergic blockade and supportive measures, including temporary hemodialysis. A right adrenalectomy was subsequently performed, leading to complete resolution of renal dysfunction and normalization of blood pressure. Conclusion: This case emphasizes the diagnostic challenge of pheochromocytoma when presenting with renal complications. Clinicians should consider adrenal tumors in the differential diagnosis of patients with unexplained acute kidney injury, as timely recognition and surgical intervention can result in full recovery.