Diagnosis and growth dynamics of adrenal incidentalomas : a 6-month retrospective analysis

Abstract

INTRODUCTION: Adrenal incidentalomas are adrenal masses discovered incidentally on imaging studies originally not performed for suspected adrenal disease.

AIM: To characterise a cohort of adrenal incidentalomas found on CT imaging the adrenal region.

METHODS: This was a retrospective analysis, taking into account all the adrenal incidentalomas discovered on CT between July and December 2014 at Mater Dei Hospital. Only lesion greater than 1cm were included in the study. These were then classified according to their radiological features. Previous CT scans and any CT scans done after the study period were also reviewed to establish any change is size of the lesions.

RESULTS: A total of 9100 CT scans were reviewed and adrenal incidentalomas were identified in 296 patients. 216 incidentalomas could be adequately classified and included in the study; 80.1% were confirmed adenomas, 12.9% metastasis, 5.6% myelolipomas and 1.3% ganglioneuromas. 49.1% of patients with an adenoma were males as opposed to 71.4% in the metastasis group. Bilateral lesions were commoner in the metastasis group (9% in adenoma vs 18% in metastasis group). Longest median radiological diameter was 18mm (IQR 14.0-24.0) in the adenoma group and 26.0mm (IQR 16.0-36.0) in the metastasis group (P<0.001). Median follow up in the adenoma group was longer in the adenoma group 20.9 months (IQR 4.5-39.0) vs 11.2 months (IQR 0-29.3) in the metastasis group (P<0.001). Median change in size was also statistically significant: 0.0mm (IQR -1-0.8) in the adenoma as compared to 22.5mm (IQR 12.5-30) in the metastasis group (P<0.001).

CONCLUSION: This study continues to confirm that adrenal adenomas are the commonest adrenal lesion encountered in clinical practice and the majority, by far remain stable in size over time.