Berke K, Constantinescu G, Masjkur J, et al. - Identification of almost all clinically relevant adrenal tumors among patients with adrenal incidentaloma may be facilitated by the combination of plasma steroid metabolomics with routinely available plasma free metanephrines and data from imaging studies.

• A retrospective cross-sectional analysis of 577 patients with adrenal incidentaloma.

• Increased plasma levels of 11-deoxycortisol, 11-deoxycorticosterone, 17-hydroxprogesterone, androstenedione and dehydroepiandrosterone-sulfate were found in adrenocortical carcinoma (ACC), whereas primary aldosteronism (PA) was characterized by elevated aldosterone, 18-oxocortisol and 18-hydroxycortisol.

• For the detection of ACC, PA and pheochromocytoma, a selection of those 8 steroids, coupled with 3 others (cortisol, corticosterone, and dehydroepiandrosterone) and plasma metanephrines, proved optimal with sensitivities of 83.3%, 90.8% and 94.8% and specificities of 98.0%, 92.0% and 98.6%.

• Further improved discrimination, especially for ACC, was achieved with addition of tumor size (100% sensitivity, 99.5% specificity).

• In contrast, discrimination of autonomous cortisol secretion and non-functional adrenal incidentaloma continued to be suboptimal (70-71% sensitivity, 89-90% specificity).