Outcomes of Adrenal Venous Sampling in Patients with Bilateral Adrenal Masses and ACTH-Independent Cushing's Syndrome.

BACKGROUND: Management of patients with bilateral adrenal masses and ACTH-independent Cushing's syndrome (AICS) is challenging, as bilateral adrenalectomy can lead to steroid dependence and lifelong risk of adrenal crisis. Adrenal venous sampling (AVS) has been previously reported to facilitate lateralization for guiding adrenalectomy. The aim of the current study was to investigate the utility of AVS using protocol from study by Young et al. in the management of patients with bilateral adrenal masses and AICS. METHODS AND DESIGN: A retrospective review of all patients with bilateral adrenal masses and AICS who underwent AVS from 2008 to 2016 was performed. AVS for cortisol and epinephrine was performed with dexamethasone suppression. The adrenal vein to peripheral vein cortisol ratios and side-to-side cortisol lateralization ratios were calculated. RESULTS: AVS was successful in 8 of 9 patients. All 8 patients had AVS results indicating bilateral cortisol hypersecretion. Six patients underwent adrenalectomy: 3 had unilateral adrenalectomy of the larger size mass, 2 had bilateral adrenalectomy (both sides >4 cm.) and 1 had stepwise bilateral adrenalectomy. Final pathology revealed macronodular adrenal hyperplasia in all 6 patients that underwent surgery. CONCLUSION: AVS was useful in excluding a unilateral adenoma as the source of AICS in this study of patients with bilateral adrenal masses and AICS. However, adrenal mass size influenced surgical decision making more than AVS results. More data are needed before AVS can be advocated as essential for management of patients with bilateral adrenal masses and AICS.