From the Guidelines
For a patient with an incidental finding of adrenal hyperplasia on CT abdomen, the next steps should include a comprehensive hormonal evaluation to determine if the hyperplasia is functional or non-functional, as recommended by the most recent guidelines 1. The initial testing should include a 1mg overnight dexamethasone suppression test to screen for autonomous cortisol secretion, as well as plasma metanephrines or 24-hour urinary catecholamines to rule out pheochromocytoma, particularly if the patient has signs or symptoms of catecholamine excess or if the adrenal mass displays >10 HU on non-contrast CT 1. Additionally, plasma aldosterone concentration to plasma renin activity ratio should be assessed to screen for primary aldosteronism, especially in patients with hypertension and/or hypokalemia 1. Physical examination should assess for clinical signs of hormonal excess such as central obesity, striae, hypertension, or hypokalemia. If hormonal testing reveals functionality, referral to an endocrinologist is warranted for specialized management. For non-functional hyperplasia, follow-up imaging in 6-12 months is typically recommended to ensure stability, as outlined in the guidelines for the management of adrenal incidentalomas 1. The size of the hyperplastic adrenal glands is also important; bilateral enlargement greater than 4 cm should raise suspicion for malignancy and may require additional imaging or consideration of biopsy. This systematic approach is necessary because adrenal hyperplasia can range from benign physiologic changes to serious hormonal disorders requiring specific treatment. It is also important to consider a multidisciplinary review by endocrinologists, surgeons, and radiologists when the imaging is not consistent with a benign lesion, there is evidence of hormone hypersecretion, the tumor has grown significantly during follow-up imaging, or adrenal surgery is being considered 1.
From the Research
Next Steps for Adrenal Hyperplasia
The next steps for a patient with an incidental finding of adrenal hyperplasia on a computed tomography (CT) abdomen involve a multimodal assessment, including:
- Assessment of malignant potential via imaging characteristics
- Evaluation of adrenal hormone excess via clinical and biochemical features
- Consideration of biopsy, surgical or medical therapy, and longitudinal surveillance
Evaluation Approach
According to 2, a case-based clinical approach to the evaluation of adrenal masses is presented, involving interpretation of multiple imaging characteristics, dynamic and static hormonal measurements, and a nuanced approach to considering interventional diagnostics, treatments, and longitudinal surveillance.
Management Recommendations
The ACR Incidental Findings Committee presents recommendations for managing adrenal masses that are incidentally detected on CT or MRI, including algorithm branches that categorize incidental adrenal masses on the basis of patient characteristics and imaging features 3.
Clinical Presentation and Imaging
Adrenal hyperplasia can be incidental or related to indolent disease process and may be related to benign or malignant etiologies causing biochemical alterations in the hypothalamic-pituitary-adrenal axis 4. CT is the primary modality of choice for adult adrenal imaging, while MRI often serves a complimentary role.
Diagnostic Workup and Imaging Features
Diagnosis and treatment of adrenal cortical hyperplasia requires a thorough clinical evaluation, and imaging has become more robust in its role in the diagnosis and treatment of adrenal conditions 5. CT and MRI are commonly used for adrenal imaging, with ultrasound and fluoroscopy used in children and foetuses to evaluate congenital adrenal hyperplasia.
Adrenal Imaging Techniques
Imaging techniques such as CT densitometry, CT washout characteristics, chemical shift MRI, PET, and PET/CT help characterize most adrenal lesions, and are critical for accurate characterization of adrenal nodules 6.