What are the implications of a 1.5 cm adrenal gland adenoma?

From the Guidelines

A 1.5 cm adrenal gland adenoma is typically a benign tumor that requires a one-time hormonal evaluation to determine if it's producing excess hormones, and if non-functioning, simple monitoring with a follow-up CT or MRI scan in 6-12 months is sufficient. For this size adenoma, I recommend a hormonal evaluation, including tests for cortisol (24-hour urine cortisol or overnight dexamethasone suppression test), aldosterone-to-renin ratio if hypertensive, and plasma metanephrines to rule out pheochromocytoma, as suggested by the most recent guidelines 1. The key points to consider in the management of a 1.5 cm adrenal adenoma include:

• A focused history and physical examination to identify signs/symptoms of adrenal hormone excess, adrenal malignancy, and/or extra-adrenal malignancy 1
• A low threshold for 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
• Screening for autonomous cortisol secretion with 1 mg dexamethasone suppression testing, and screening for primary aldosteronism with an aldosterone-to-renin ratio in patients with hypertension and/or hypokalemia 1
• If the adenoma is non-functioning and the patient has no symptoms, no further imaging follow-up or functional testing is required, as the risk of malignancy is very low for adrenal masses smaller than 4 cm 1. The management of a 1.5 cm adrenal adenoma should prioritize the patient's quality of life, minimizing unnecessary tests and procedures, while ensuring that any potential hormone-producing tumors are identified and treated appropriately, as recommended by the most recent guidelines 1.

From the Research

Adrenal Gland Adenoma Characteristics

• Adrenal adenoma is the most common adrenal tumor, frequently encountered on cross-sectional imaging performed for unrelated reasons 2
• Adrenal adenomas can manifest various imaging features on CT, MRI, and positron emission tomography/CT 2
• The size of the adrenal gland adenoma can vary, with a mean size of 6.21 cm reported in one study, although sizes can range from 1.4 to 13.7 cm 3

Evaluation and Management

• The evaluation and management of adrenal masses, including adenomas, require a comprehensive systematic approach, including assessment of clinical history, physical examination, dynamic hormone evaluation, and imaging modalities 4
• Imaging techniques such as CT densitometry, CT washout characteristics, chemical shift MRI, PET, and PET/CT can help characterize adrenal lesions, including adenomas 5
• The approach to evaluating and managing bilateral adrenal masses follows the same protocol as unilateral adrenal masses, with consideration of unique features such as differential diagnosis, evaluation, and management depending on etiology 4

Biochemical Composition

• The biochemical composition of adrenal gland tumors, including adenomas, can be analyzed using Fourier transform infrared (FTIR) microspectroscopy 6
• Adenomas have been found to have higher levels of lipids compared to pheochromocytomas, while pheochromocytomas have higher levels of proteins 6
• Differences in nucleic acids and carbohydrates have also been observed in adrenal gland tumor types, including adenomas 6

Specific Considerations for 1.5 cm Adrenal Gland Adenoma

• While the provided studies do not specifically address the evaluation and management of a 1.5 cm adrenal gland adenoma, the general principles of evaluation and management outlined in the studies can be applied 3, 4, 2, 5
• The size of the adenoma, 1.5 cm, is relatively small compared to the mean size reported in one study, and may not require immediate intervention, but rather careful evaluation and monitoring 3