From the Guidelines
Functioning adenomas (adrenal gland tumors) should be monitored with imaging and laboratory tests at regular intervals, with the frequency depending on the size and potential for malignancy.
Recommended Imaging and Laboratory Surveillance
- For small adenomas (< 3 cm), no extensive workup is usually justified, but endocrinologic evaluation should be considered to rule out subclinical hyperfunction 1.
- For adenomas between 3 and 5 cm, follow-up CT or MRI can be used to assess the nature of the incidentaloma, and endocrinologic evaluation should be considered 1.
- For adenomas larger than 5 cm, removal is recommended due to the higher risk of malignancy 1.
- CT or MRI of the abdomen and chest should be performed at regular intervals (e.g., every 6-12 months) to monitor for potential metastases or local invasion 1.
- Biochemical testing, including plasma or urinary metanephrine, normetanephrine, chromogranin A, and methoxytyramine, should be repeated at regular intervals (e.g., every 3-6 months) to monitor for hormonal excess or malignancy 1.
- FDG-PET can be used to evaluate the option of radionuclide-based therapy in patients with non-resectable tumors or to assess metastatic risk 1.
- The follow-up interval can be adjusted based on the patient's risk factors, such as tumor size, extra-adrenal location, or SDHB mutation, with more frequent monitoring for patients at higher risk of malignancy 1.
From the Research
Imaging Surveillance Frequency
- For benign adrenal nodules, including functioning adenomas, dedicated adrenal imaging is required 2
- Recent advances in imaging allow for discrimination between risk categories, with homogeneous lesions with Hounsfield unit (HU) ≤ 10 on unenhanced CT being benign and not requiring additional imaging independent of size 2
- For lesions >4 cm that are inhomogeneous or have HU >20, surgery is usually the management of choice due to high risk of malignancy 2
Laboratory Surveillance Frequency
- Every patient with an adrenal nodule requires a thorough clinical and endocrine work-up to exclude hormone excess, including measurement of plasma or urinary metanephrines and a 1-mg overnight dexamethasone suppression test 2
- Patients with mild autonomous cortisol secretion (MACS) should be screened for potential cortisol-related comorbidities, such as hypertension and type 2 diabetes mellitus 2
- Follow-up is indicated for non-operated patients, with guidance provided for management of patients with bilateral incidentalomas, extra-adrenal malignancy and adrenal masses, and young and elderly patients with adrenal incidentalomas 2
Specific Recommendations
- Surgery is not usually indicated in patients with an asymptomatic, nonfunctioning unilateral adrenal mass and obvious benign features on imaging studies 2
- For patients with MACS and relevant comorbidities, surgical treatment should be considered in an individualized approach 2
- The appropriateness of surgical intervention should be guided by the likelihood of malignancy, presence and degree of hormone excess, age, general health, and patient preference 2