(1.02) Adrenal Venous Sampling: A Challenging yet Vital Tool for Discriminating Unilateral and Bilateral Cortisol Production in Cushing's Syndrome"

Diagnosing and treating ACTH-independent Cushing's syndrome with bilateral adrenal masses can pose challenges. Adrenal venous sampling is a useful technique to identify and determine the functional lesions' lateralization. In this report, we describe the case of a middle-aged woman with Cushing's syndrome and bilateral adrenal masses.

Case(s) Description :

In 2021, a 54-year-old woman with a medical history of multinodular goiter, hypertension, subclinical hyperthyroidism, hyperlipidemia, and obesity visited our clinic. She presented with specific symptoms, including truncal obesity, proximal muscle weakness, thinning of the arms and legs, skin atrophy, a distinct buffalo hump, and a gradual weight gain of 8 kg over a period of 7 months. Her body mass index (BMI) was calculated to be 31 kg/m2 (height: 163 cm; weight: 78 kg). The patient denied experiencing easy bruising, and we did not observe any purple striae or supraclavicular fat pads. She was currently receiving treatment for hyperlipidemia with Atorvastatin 20 mg daily and subclinical hyperthyroidism with Methimazole 10 mg and Propranolol 40 mg twice a day. The patient sought our consultation due to her progressive weight gain.As part of the investigation into her obesity, various laboratory tests were conducted. These included a morning cortisol level of 25.1 μg/dL, an ACTH level below 5 pg/mL, and a urinary free-cortisol level of 79 μg/day. 1 mg 48-hour low-dose dexamethasone suppresion test was performed,resulted  plasma cortisol level of 3.2 μg, and a urinary free-cortisol level of 79 μg/day To further assess the condition, adrenal computed tomography (CT) was performed, which revealed bilateral, round, and smooth-contoured nodules measuring 1.5 cm in the right adrenal gland and 3 cm on the left side . The CT scan could not definitively determine whether either or both of the nodules were responsible for cortisol hypersecretion.To identify and localize the source of the excessive cortisol secretion, we conducted adrenal venous sampling after the administration of dexamethasone. plasma adrenaline levels: right adrenal vein, 4187pg/mL and left adrenal vein, 878pg/mL (inferior vena cava adrenaline, 23.15pg/mL). The adrenal vein-to-peripheral vein cortisol ratio (AV/PV gradient) was 6.23  on the right side and 6.53 on the left side, with a right-to-left lateralization ratio of 14.29.The patient will undergo laparoscopic right adrenalectom

Discussion :

The clinical presentation of Cushing’s syndrome must be considered in patients with hyperthyroidism with progressive weight gain, protein-wasting features, and proximal muscle weakness. Localization of the lesion is necessary for the diagnosis and treatment of ACTH-independent Cushing’s syndrome due to bilateral adrenal masses Adrenal venous sampling can be used in patients with bilateral adrenal masses to localize and lateralize the lesion. Mnaging unilateral adrenal adenoma is easier than bilateral adrenal adenoma, so surgical option is preferable before medical managment.