Endocrine Abstracts

Introduction: Patients referred for adrenal incidentalomas (AI) are increasing. Current guidelines are controversial on diagnosis and length of follow-up.

Objectives: Analyze clinical, radiologic and hormonal characteristics of patients with AI. Evaluate the number and usefulness of tests needed for diagnosis, clinical outcome and follow up.

Material and methods: Observational, retrospective study in patients with AI in our endocrinology department from 1993–2014, including oncologic patients. Those with hormonal hyperproduction symptoms were excluded.

Results: One hundred and seventy six patients (111F/65M) were included. Medium age: 59.68±12.54 (31–84) years. Radiologic study: Medium radiologic tests per patients was 4.14±2.69 (1–14) during a medium follow up: 3.65±3.75 (0–18) years. Initial radiological diagnosis: 13% undetermined lesions, 69% adenoma, 6% hyperplasia, 3% mielolipoma, 2% malignant and 1% pheochromocytoma. 84% were <4 cm and 29% were bilateral. Functional study included: 1 mg dexamethasone suppression test (1 mg DST), basal ACTH, UFC and urinary catecholamine. Medium follow up: 3.75±3.5 (0–17) years. 75% patients had at least one altered test; 1 mg DST was altered in 80 patients (47.3%), only 33 patients (19%) met criteria for subclinical Cushing syndrome (SCS). Functional diagnosis: 64% (107) nonfunctioning, 19% (33) SCS, 4% (8) pheochromocytomas, 3% (5) clinical adrenal Cushing(CAC), 1 ACTH-dependent Cushing. Malignancy: Metastases were diagnosed in six patients, all with previous cancer history. No adrenal corticocarcinoma (ACC) was diagnosed. Outcomes: seven patients developed SCS, no patients with SCS developed CAC. Four tumors had significant growth: two were metastases. No patients developed malignant transformation to ACC.

Conclusions: The majority of AI are small, benign, non-functioning and remained stable even in patients with long follow up. Most of them were well defined with the first radiologic test. In our serie SCS is the most frequent hormonal alteration, but transformation in CAC was not found. Low incidence of malignant transformation in non-oncologic patients and the lack of hyperfunction development should make us reconsider our practice to avoid prolonged follow up and unnecessary testing.