Endocrine Abstracts

Background: Currently, the European Society of Endocrinology guidelines asserted against additional imaging during follow-up (FUP) in patients with non-functioning adrenal masses <4 cm in size with clear benign features on imaging studies. Our analysed literature data suggests that an increase (minimum 1 cm) in an initially benign adrenal mass during follow-up occurs in 3.5–20% of patients with adrenal incidentalomas.

Aim: To analyse the change in size of non-functioning adrenal masses detected by computerized tomography (CT) in patients who had FUP at VUHSK from 2010 to 2017.

Materials and methods: A retrospective single-center study of non-functioning adrenal masses was conducted. The following ICD-10 classification codes were used to retrieve cases from our database: D35.0; D44.1; C74.1; C74.9; E26.0; E27,8; E24,8. For the retrospective study of CT scans, electronic data capture system was applied. We considered significant increase as the growth in tumour size by more than 20% and a minimum 5 mm increase in largest diameter.

Results: 1250 patients were assessed for adrenal masses from 2010 to 2017. Out of 1250 patients there were 302 subjects (24.16%) with adenomas and at least one FUP and obvious benign features on CT scan were seen, these 302 patients were included in the study. Mean age of study subjects were 65.4 years, 83.2% of them were female. The average tumour size at baseline was 21.5±10.9 mm. Average follow-up (FUP) time was 3.16 years (from 2 to 8) during which tumour size increased in 123 (40,7%), decreased – in 105 (34,8%), did not change - in 74 (24,5%) of cases. Significant increase in tumour size was observed in 22 (7,3%) of cases. Average size of 22 significantly enlarged tumours changed from 19.0±8.5 mm to 33.9±14.9 mm during FUP. Significantly increased tumours were more common in younger age subjects. Subjects age during the tumour discovery: significantly increased 57.3 years (±10.1), insignificantly increased – 61.4 years (±10.5), stayed the same size – 62.6 years (±11.0), P=0.02955. None of the observed tumours became functioning during the observation period.

Conclusions: We have demonstrated a significant enlargement of initially benign non-secreting adrenal masses during 3.16 years FUP in 7.3% of cases and the association with younger age. Nevertheless, larger prospective studies with extended FUP are necessary to affirm the time-frame for suitable FUP schemes in order not to miss the significant enlargement of the adrenal mass that necessitate surgical procedures.