Most True Adrenal Incidentalomas Lack Proper Evaluation

Abstract

Abstract Although the majority of true adrenal incidentalomas are benign and non-functional, appropriate workup is critical to rule out cancers as well as metabolic and cardiovascular diseases such as Cushing’s syndrome, primary aldosteronism (PA), and pheochromocytoma (PCC). The AACE/AAES and ENSAT guidelines recommend that all adrenal incidentalomas be evaluated for worrisome radiographic features and that all patients have initial biochemical work up to evaluate for hypercortisolism and pheochromocytoma as well as primary aldosteronism if hypertensive. Despite this, adrenal incidentalomas often are not evaluated properly leading to delayed diagnoses and potential complications from dysregulated hormone production. To determine if true adrenal incidentalomas are managed properly in our hospital system, we conducted a retrospective chart review. All CT scans (chest or abdomen) of adult patients conducted at the University of Colorado Hospital system between August 2011 and December 2016 were assessed (N=86,771). Of these, 305 scans identified true adrenal incidentalomas. CT scans done for patients with genetic conditions predisposing to adrenal nodules or done for an indication suggestive of adrenal disorder were excluded. From the 305 patient scans, 347 adrenal nodules were identified. Most patients (N=263, 86%) had one adrenal nodule; 42 (14%) had multiple nodules. Mean age of the cohort was 60±12.58 years old (range 21–88), and the majority were female (60.7%). The nodules had a mean size of 2.23±1.42 cm, range 0.5–11.2 cm. Most nodules were identified on CT scans with contrast (79%, N=241). Of the 64 scans (21%) done without contrast, 43% of the nodules had non-contrast enhanced (NCE) Hounsfield units (HU) less than 10, suggesting benign adenomas. Thirty-nine nodules (57%) had NCE HU greater than 10; eight of those were surgically removed (4 metastases from other primary cancers; 2 PCC; 2 lipid poor adrenal cortical adenomas). Most nodules were not biochemically evaluated. Only 64 of the 305 patients (21%) were tested for hypercortisolism (1mg ODST in 35; 24hr UFC in 29). Of those, three (0.1%) were diagnosed with Cushing’s syndrome. Only 82 patients (27%) were evaluated for PCC with plasma and/or 24hr urine metanephrines. Of these, 10 were diagnosed with PCC (3.3%). Only 24 patients (7.9%) were screened for PA with serum aldosterone and plasma renin activity, and four (1.3%) were positive. Taken together, of the 305 patients with adrenal incidentalomas, only 29 (9.5%) met guideline recommendations for biochemical work up for both hypercortisolism and PCC. Of those, 10 had a history of hypertension, yet only 5 were evaluated for PA. In summary, less than 10% of true adrenal incidentalomas had the proper biochemical evaluation. This suggests there are likely missed functional nodules leading to delayed or missed diagnosis possibly contributing to cardiovascular and metabolic consequences.