An Incidental Finding of a Large Pheochromocytoma in an Asymptomatic Male: A Case Report

Pheochromocytoma is a rare neuroendocrine tumor that secretes excess catecholamines. Patients present with a classical triad of headache, palpitations, and sweating. If untreated, pheochromocytoma can result in life-threatening cardiovascular complications. Diagnosing pheochromocytoma is often challenging due to its atypical presentation, infrequent occurrence, and the fact that a small number of patients are asymptomatic, and very few pheochromocytomas are malignant. Here, we report a case of an 80-year-old man who was referred to the endocrine clinic after an incidental finding of an adrenal tumour. He did not have any symptoms related to pheochromocytoma. He had a 20-year complex cardiac history, including nine cardiac ischemic events, seven coronary artery stent placements, and a coronary bypass grafting procedure. He remained symptomatic, and coronary angiographic studies continued to demonstrate obstructed coronary arteries despite being on adequate secondary prevention. He also had type 1 diabetes, hypertension, and subclinical hypothyroidism. Both urinary and plasma catecholamines were elevated, confirming a diagnosis of pheochromocytoma. A computed tomography scan demonstrated a right subpleural mass and a left adrenal mass. A dedicated magnetic resonance imaging scan revealed a large left heterogenous adrenal lesion. A fluorodeoxyglucose positron emission tomography scan suggested that the subpleural mass and the adrenal mass could be malignant. He was commenced on medical treatment (alpha-blockade) and had no further ischaemic-related symptoms or cardiac events. Serial scans thereafter have indicated no increase in the size of both lesions. This case serves as a reminder and highlights the importance of asymptomatic pheochromocytoma.