Prevalence of Subclinical Cushing's Syndrome in 70 Patients with Adrenal Incidentaloma: Clinical, Biochemical and Surgical Outcomes

Abstract

Abstract. Subclinical Cushing's syndrome (SCS) is being detected with increased frequency in patients with adrenal incidentaloma. In the current study, we evaluated the prevalence of SCS in 70 patients with adrenal incidentaloma and compared the main findings on them with other patients with nonfunctional adrenal incidentaloma (NFA). Overnight 3 mg dexamethasone (DXM) suppression test to exclude cortisol hypersecretion, and high dose DXM suppression test to find out patients with SCS, were applied to all subjects. Afterwards, biochemical and clinical findings of patients with SCS were compared with the other patients with NFA. Four of the 70 patients with adrenal incidentaloma were found to have SCS, with a prevalence of 5.7%. Basal ACTH and DHEA-S levels were significantly lower (p<0.05 and p<0.01, respectively), and midnight cortisol and 24-hour urinary free cortisol levels were significantly higher in patients with SCS (p<0.001 and p<0.05, respectively). Biochemical and metabolic bone parameters were similar in patients with SCS and in patients with NFA. Hypertension, diabetes mellitus, and obesity were more common in patients with SCS. One of the patients with SCS developed adrenocortical insufficiency following unilateral adrenalectomy which lasted for about 6 months. Suppressed ACTH and DHEA-S levels, and high midnight cortisol levels may be some clues for SCS in patients with adrenal incidentaloma. Since patients with SCS frequently have risk factors for atherosclerosis such as hypertension, diabetes, and obesity, and the surgical management of SCS with adrenalectomy may offer an advantage. Patients undergoing adrenalectomy should be followed for the development of adrenal insufficiency.

Post-surgical hypocortisolism after removal of an adrenal incidentaloma: is it predictable by an accurate endocrinological work-up before surgery?

“…Indeed, some authors recommend a substitutive steroid therapy in all patients (10,17), while others only in those with pre-surgically suspected SH (5,7,18). This discordance depends on the fact that the prevalence of post-surgical hypocortisolism has been differently estimated in the different series, even in the more recent studies (12)(13)(14)(15)(16)(17)(18). In our opinion, this could be firstly due to the characteristics of the disease per se.…”

“…However, so far, no studies specifically investigated the possible association between the pre-surgical biochemical diagnosis of SH and the subsequent presence of post-surgical hypocortisolism. The prevalence of post-surgical hypocortisolism in patients, with and without SH, who underwent unilateral adrenalectomy for AI, varies depending on the criteria used to diagnose SH (12)(13)(14)(15)(16)(17)(18). In addition, most studies considered only post-surgical basal cortisol level or the presence of symptoms suggesting adrenal failure as a diagnostic tool for post-surgical hypocortisolism (12,15,17,18).…”

Pros and cons of dexamethasone suppression test for screening of subclinical Cushing’s syndrome in patients with adrenal incidentalomas

“…Conversely, 1-mg dexamethasone is usually sufficient to suppress cortisol secretion by the non-adenomatous adrenal tissue that is driven by pituitary ACTH, while higher dexamethasone doses are not more effective (6,(26)(27)(28)(29)(30). As a matter of fact, the phenomenon of resistance to increasing doses of dexamethasone has been already observed in small groups of patients submitted to both tests (7,31,32). Spontaneous fluctuation of cortisol secretion over time, that has been demonstrated also in subclinical Cushing's syndrome (33), may contribute to the finding that cortisol was paradoxically higher after 8-mg than 1-mg DST.…”

Decrease of Arterial Hypertension After Adrenalectomy in Patients Without Confirmation of Adrenal Tumour Hyperfunction

“…1. Diagnostic imaging included sonography (44 cases), computed tomography (41), magnetic resonance imaging (10) and arteriography (performed in order to exclude renal artery stenosis, n=13) ( fig. 1).…”

“…Surgery is a well established method of treatment in patients with confirmed endocrine hyperactivity of adrenal tumours including pheochromocytoma (1)(2)(3)(4), Conn syndrome (5)(6)(7)(8), overt or subclinical Cushing syndrome (9)(10)(11)(12), as well as with lesions that possess morphological features of malignancy in diagnostic imaging (13)(14)(15)(16). On the other hand, constant progress in diagnostic imaging techniques (computed tomography and magnetic resonance imaging) results in an increasing number of incidentally diagnosed adrenal tumours -inci-dentalomas (17)(18)(19)(20).…”