Endocrine Abstracts

Background

Adrenal incidentaloma (AI) is an adrenal mass discovered accidentally during abdominal or chest imaging techniques not aimed to adrenal gland assessment. The management of non-functional adrenal adenomas (NFAI) at least 4 cm is still a matter of debate as it is unclear whether imaging can be used to characterize their potential malignancy. Moreover, the risk of new hypersecretion in nonoperated tumors is uncertain. Our aim was to better characterize these large NFAIs.

Objective

Description and assessment the radiological parameters of NFAI on computed tomography (CT).

Materials and methods

We performed a retrospective study in City Hospital No. 40 in Yekaterinburg from January 2009 to December 2019, involving 89 operated patients NFAI. For all patients, we assessed history, physical examination, radiological parameters of NFAI by CT scan (native Hounsfield unit [HU]), maximum diameter and blood investigations (glycated haemoglobin, adrenocorticotropic hormone, aldosterone, renin, aldosterone/renin ratio, normetanephrine, metanephrine, dehydroepiandrosterone sulphate, cortisol and 1 mg overnight dexamethasone suppression test).

Results

Criteria for the diagnosis of malignant NFAI were: a combination of size and HU. 89 operated patients NFAI consist of 3 groups. 1 – the group with native CT < 10 HU (n-44): adrenal mass 5.87 ± 2.98 cm (95% CI 4.99–6.75 cm), aged 46.16 ± 12.02 years (95% CI 42.61–49.71 years), observation time before surgery 2.21 ± 3.13 years (95% CI 1.28–4.05 years); 2 – the group with native CT inhomogeneous density (n-14): adrenal mass 5.60 cm (IQR 4.0–6.75 cm), aged 60.5 years (IQR 47.5–63.25 years), observation time before surgery 0.5 years (IQR 0.38–1.44 years). 3 – the group with native CT ≥ 10 HU (n-31): adrenal mass 6.0 ± 3.13 cm (95% CI 4.9 – 7.1 cm), aged 45.39 ± 13.52 years (95% CI 40.63 – 50.15 years), observation time before surgery 2.27 ± 3.02 years (95% CI 1.21 – 3.34 years).

Conclusions

Patients treated by adrenalectomy had tumors > 5.6 cm, high or different density areas CT (P < 0.05).

Keywords: Adrenal incidentaloma, non-functional adrenal adenoma.