Correlation Between Size and Function of Unilateral and Bilateral Adrenocortical Nodules: An Observational Study

Area of Science:

• Endocrinology
• Radiology
• Cardiovascular Medicine

Background:

• Adrenal incidentalomas are common, found in 5% of adults.
• Autonomous cortisol secretion from these tumors elevates risks of metabolic syndrome and cardiovascular disease.

Purpose of the Study:

• To investigate the association between adrenal nodule size, measured via CT scan, and the presence of autonomous cortisol secretion.

Main Methods:

• A prospective study involved 73 patients with adrenal incidentalomas and 34 controls.
• Measurements included maximum nodule diameter on CT, baseline serum cortisol, and cortisol levels after ACTH stimulation and dexamethasone suppression tests.
• Statistical analyses included Spearman correlation, t-tests, ANOVA, and multivariate analysis.

Main Results:

• Adrenal nodules were larger on average in the right adrenal gland compared to the left in both unilateral and bilateral cases.
• Patients with incidentalomas exhibited higher baseline serum cortisol levels than controls.
• Cortisol suppression after dexamethasone was significantly lower in patients with incidentalomas (33% bilateral, 62% unilateral) compared to controls (100%).
• A significant positive correlation was found between maximum nodule diameter and both baseline and post-dexamethasone serum cortisol levels.

Conclusions:

• Increasing adrenal nodule size is linked to more severe hypercortisolism and reduced dexamethasone suppression.
• These findings highlight the importance of nodule size in assessing risks associated with adrenal incidentalomas.
• Patients with larger nodules warrant further evaluation for potential surgical management due to elevated risks of metabolic syndrome and cardiovascular mortality.