Two thirds of patients were identified because of adrenal incidentalomas. 

In recent years, pheochromocytomas are detected increasingly in patients with incidentally discovered adrenal masses, rather than in patients with classic adrenergic symptoms. This report describes 167 patients with pheochromocytoma who were evaluated and treated at a U.K. referral center between 2010
and 2022. Findings were as follows:

After excluding 20 patients whose pheochromocytomas were detected by screening (because of family history), 69% of cases were diagnosed in patients with adrenal incidentalomas, 28% in patients with adrenergic symptoms/uncontrolled hypertension, and 3% in patients with acute cardiomyopathy.

• 40% of patients whose pheochromocytomas were incidentalomas described adrenergic symptoms in retrospect, and 36% had known hypertension.
• Patients with incidentalomas were much older than those who presented because of adrenergic symptoms/uncontrolled hypertension (median ages, 62 vs. 42).
• Median metanephrine levels were much higher in patients with adrenergic symptoms/uncontrolled hypertension than in those with incidentalomas (≈15-fold vs. 5-fold elevation above upper limit of normal).
• On unenhanced computed tomography (CT), no pheochromocytoma was a homogeneous lesion with unenhanced density ≤10 Hounsfield units (HU).
• Four patients had metastatic lesions at presentation.

COMMENT
This case series provides a good contemporary overview of pheochromocytoma. Two guidelines published in 2023 recommend that patients with adrenal incidentalomas generally should undergo evaluation for pheochromocytoma; the exception is the asymptomatic patient whose CT-identified lesion is typical for a benign adenoma — i.e., homogeneous, unenhanced density ≤10 HU (Eur J Endocrinol 2023; 189:G1; J Urol 2023; 210:590). — Allan S. Brett, MD

Dr. Brett is Clinical Professor of Medicine at the University of Colorado School of Medicine, Aurora.

Aggarwal S et al. Pheochromocytomas most commonly present as adrenal incidentalomas: A large tertiary center experience. J Clin Endocrinol Metab 2024 Jan; 109:e389. (https://doi.org/10.1210/clinem/dgad401)

NON-2024-2054