The recent development of quantitative steroid metabolome profiling could be of interest for the positive diagnosis of mild autonomous cortisol-secreting adenoma (MACS). The aim of the study is to develop a predictive model of MACS status or non-secreting adenoma (NSA) based on a panel of 19 serum steroids and three clinico-biological parameters (body mass index or BMI, fasting glycaemia, blood pressure) and to estimate its performance for the diagnosis of MACS in a cohort of patients followed in the endocrinology department of Bordeaux University Hospital.

Steroid assays are a central element in the aetiological diagnosis of adrenal tumors, but they are still limited to single assays (e.g. cortisol in Cushing's syndrome, aldosterone in primary hyperaldosteronism, etc.) which only partially reflect the endocrine disturbances caused by adrenal pathologies. The recent development of quantitative profiling of the circulating steroidome could lead to a reconsideration of the role of these single steroid assays in endocrinology. This involves simultaneously measuring of multiple steroids from a single blood or urine sample using liquid chromatography-mass spectrometry (LC-MS/MS). The steroid fingerprint obtained enables adrenal masses to be better characterised. Using machine learning methods, a predictive model of MACS status or NSA based on a panel of 19 serum steroids measured by LC-MS/MS and three clinico-biological parameters (body mass index or BMI, fasting glycaemia, blood pressure) will be develop. The blood sample used for the steroid assay will be taken at inclusion during a blood test carried out as part of routine care. Clinical, biological and morphological data obtained during the 24 months of study follow-up and as part of routine care will be collected retrospectively. All assays will be carried out in the hormonology laboratory of Bordeaux University Hospital (BUH) by LC-MS/MS. The development of the MACS/ANS status prediction model will be carried out by the BUH Methodological Support Unit for Clinical and Epidemiological Research (USMR). The performance and prognostic value of this new tool will be estimated in a cohort of patients followed in the BUH endocrinology department.

Inclusion Criteria:

MACS and ANS group:

• 18 years ≤ Age
• Patient with one or more unilateral or bilateral adrenal nodules with spontaneous density < 20 HU on CT and major axis ≥ 1 cm and without associated overt pathological hormonal secretion.
• Patient with one or more uni or bilateral adrenal nodules not meeting the above density criteria but without malignancy criteria and stable in size on imaging after at least 6 months of follow-up and without associated overt pathological hormone secretion.
• Written consent of the patient for his participation in the research (at the latest on the day of inclusion and before any examination required by the research).
• Subject affiliated to or benefiting from a social security scheme.

Diagnostic criteria (determined after blood sampling) for continuation of the study:

MACS group:

• At least two elevated DST1mg (Cortisol > 50 nmol/L or 1.8 µg/dL) AND
• a plasma ACTH level ≤ 20 pg/mL

ANS group:

- Normal DST1mg (Cortisol ≤ 50 nmol/L or 1.8 µg/dL). The definition criteria for MACS and ANS were based on the latest recommandations of learned societies.

Controls group:

• patients followed in the endocrinology department, free of any known adrenal pathology and with a DST1mg test < 50nmol/L.
• matched for age and sex to patients in groups 1 and 2.

Non -inclusion criteria:

• Adrenal incidentaloma < 1 cm in size.
• Use of exogenous corticosteroids, whether systemic or local (inhaled, eye and ear drops, ophthalmic ointment, topical skin products, joint infiltration) in the 6 months prior to the trial, and drugs that interfere with the metabolism of dexamethasone.
• Pregnant women.
• Patients with any other life-threatening condition.
• Patients with an intercurrent pathology at the time of blood sampling (fever, COVID infection, influenza....).
• Urinary free cortisol (UFC) > at the limit of laboratory normality.
• Patients under court protection.

The feasibility of the project is ensured by active and ongoing collaboration between:

• The endocrinology department at Bordeaux University Hospital, which has recognized expertise in adrenal disorders, particularly MACS (participation in drafting European recommendations on adrenal incidentalomas, reference centers for rare adrenal diseases). It has strong potential for recruiting patients monitored for adrenal disorders throughout the Nouvelle-Aquitaine region.
• The hormone department at Bordeaux University Hospital, itself a reference center for LC-MS/MS steroid dosing and active in research projects on this topic.