Adrenal Incidentaloma Management Guidelines

Lesion Characterization and Follow-up

The American Urological Association recommends that patients with benign non-functional adenomas <4 cm, myelolipomas, and other small masses containing macroscopic fat do not require any additional follow-up imaging or functional testing after initial characterization 1, 2
Lesions with homogeneous appearance and <10 HU on non-contrast CT, no hormonal hypersecretion on initial screening, and size <4 cm do not require further imaging or functional testing 1, 2

For lesions ≥4 cm, repeat imaging at 6-12 months is recommended, even if the lesion appears benign on initial CT, due to the higher risk of malignancy 1, 3, 4
Most surgically resected pheochromocytomas and adrenocortical carcinomas were >4 cm at diagnosis, supporting the need for closer surveillance of larger lesions 4

A growth rate of <3 mm/year indicates no further imaging or functional testing is required 1, 2, 4
A growth rate of >5 mm/year suggests adrenalectomy should be considered after repeating functional workup 1, 2, 4

The American Urological Association guidelines (2023) do not recommend repeat hormonal testing if initial workup was normal 1
The American Association of Clinical Endocrinologists and American Association of Endocrine Surgeons guidelines recommend annual hormonal panel for 5 years 6

Patients with a history of extra-adrenal malignancy require closer evaluation, even for smaller lesions, due to a metastatic risk ranging from 25-72% depending on the primary tumor 7
Young adults, children, and pregnant patients should undergo expedited evaluation, as adrenal lesions are more likely malignant in these populations 3, 4

Routine adrenal mass biopsy is not recommended for workup of adrenal incidentalomas, as it is rarely indicated and carries risks including potential tumor seeding 1, 2
Initial hormonal evaluation should not be skipped, even for radiologically benign-appearing lesions, as approximately 5% harbor subclinical hormone production requiring treatment 8