Conventional adrenal venous sampling (cAVS) is useful for identifying laterality of primary aldosteronism (PA). In cAVS, plasma cortisol concentration (PCC) is used for normalization of plasma aldosterone concentration (PAC). We have developed a novel super-selective adrenal venous sampling (ssAVS) method using a specialized microcatheter, which collect blood samples from adrenal tributary veins (TVs). PAC in ssAVS samples do not require PCC-normalization since the samples contain a limited amount of systemic venous blood, if any. The ssAVS method enabled us to identify and surgically treat adrenal segments responsible for excess aldosterone production in bilateral PA cases. In this study, we aimed to determine if ssAVS is useful for evaluating cortisol production in a PA case with subclinical Cushing’s syndrome (SCS). A computed tomography identified bilateral adrenal tumors (Fig. 1A). Right adrenal venography identified superior TV (blue arrow in Fig. 1B), lateral TV (red) that was downstream of the tumor, and inferior TV (green). Left adrenal venography identified superior-median TV (red arrow in Fig. 1C) with a filling defect presumably due to the left adenoma (green), superior-lateral TV (blue), and lateral TV (yellow). Blood samples were individually collected from these bilateral TVs by ssAVS. The PCC in right lateral TV (1,150 µg/dL) and PAC in left superior-median TV (30,400 pg/mL) were much higher than the others (indicated in Fig. 1B and 1C), suggesting that the right and left tumors were a cortisol-producing adenoma (CPA) and aldosterone-producing adenoma, respectively. Left partial adrenalectomy was performed and PA was cured. SCS is currently followed up without treatment, because his SCS has not caused hypertension or impaired glucose tolerance. Pathological diagnosis of left tumor was adrenal adenoma in hematoxylin and eosin staining (T in Fig. 1D), which was positive for aldosterone synthase (AS, Fig. 1E) but not for 11β-hydroxylase (11β, cortisol producing enzyme, Fig. 1F). 11β was negative in adjacent normal adrenal (N in Fig. 1F), suggesting that cortisol production was suppressed by the possible right CPA. These enzyme expression was consistent with ssAVS data. This study suggested that ssAVS is useful for evaluating cortisol production in adrenal adenomas.
