Epinephrine to the Rescue: Identifying the Offending Side in Bilateral (B/L) Macronodular Adrenal Hyperplasia (BMAH) With Cushing Syndrome (CS) and Hyperaldosteronism

Abstract

Management of ACTH-independent CS in the setting of B/L adrenal masses can be challenging. We present a patient with concomitant cortisol and aldosterone hypersecretion and B/L adrenal masses who was treated with unilateral adrenalectomy (UA) based on simultaneous B/L adrenal vein sampling (AVS) results normalized to plasma epinephrine levels, to correct for flow and dilution. A 60-year-old lady presented for evaluation of incidentally discovered B/L adrenal masses. CT abdomen with contrast revealed B/L lobulated adrenal glands measuring 3.4 x 5.5 x 4.1 cm on the right and 3.8 x 4.2 x 2 cm on the left (pre contrast density of 37 and 44 Hounsfield Units respectively). She had a recent diagnosis of HTN and prediabetes. She reported fatigue, easy bruising, and muscle weakness. Family history was notable for a sister with CS and B/L adrenal masses who was successfully treated with UA. On physical examination her BP was 160/94 mm Hg and she did not have an obvious cushingoid appearance. Laboratory testing included an elevated AM serum cortisol level of 16.6 mcg/dL following 1 mg of dexamethasone given at 11 pm the previous night. ACTH was <1.0 pg/mL consistent with ACTH-independent CS. She had a serum aldosterone level of 26.6 ng/dL(4.0 - 31.0 ng/dL),simultaneous plasma renin activity of 0.5 ng/ml/hr (0.5–4 ng/ml/hr) and serum potassium level of 4.4 mmol/l. She underwent B/L simultaneous AVS. Given concomitant hyperaldosteronism, plasma epinephrine levels were measured to determine successful catheter placement and to correct for flow and dilution between the adrenal veins. Right adrenal vein to peripheral vein cortisol ratio was 9.27 (> 6.5) consistent with cortisol hypersecretion. The right to left cortisol ratio was 2.3 (>/= 2.3), consistent with right sided predominance. Right to left ratio of the epinephrine corrected cortisol level was 2.7. She underwent right adrenalectomy, and pathology showed macronodular adrenal hyperplasia. Postoperatively, she had resolution of HTN and normalization of 24 hour urine free cortisol. UA is increasingly becoming recognized as a successful treatment for BMAH due to lower risk of adrenal crisis when compared to B/L adrenalectomy. In a recent publication, remission from CS was seen in 94.4 % of patients with BMAH following UA, with recurrence in 19% of patients. The mean time to recurrence was 5 years. We utilized cutoff values that were previously reported for cortisol lateralization in interpreting AVS. Our patient attained remission of CS 9 months post UA. Epinephrine levels were not significantly different between the adrenal veins, possibly due to simultaneous AVS, so we were also able to calculate epinephrine corrected cortisol ratios. Simultaneous B/L AVS with epinephrine to localize autonomous hypercortisolism in the setting of concomitant hyperaldosteronism can be beneficial in guiding surgical management of patients.