[Adrenal incidentalomas]

Abstract

Adrenal incidentalomas are called as a disease of modern technology because increased availability and accuracy of imaging techniques lead to increased incidence of incidentally discovered adrenal masses. Adrenal incidentalomas are found in about 0.35-4.36% of abdominal CT scans performed for purpose other than suspicion of adrenal diseases. However, in autoptic studies the percentage of incidentally discovered adrenal tumours in much higher, in some of then being even more than 20%. Important component of differential diagnosis is endocrinological examination aimed to reveal potential autonomous hormonal overproduction. Approximately more than 10% of adrenal incidentalomas is characterized by autonomous cortisol production, 5-10% is phaeochromocytomas and 5-7% is aldosteron producing adenomas. Vast majority of adrenal incidentalomas are nonfunctioning tumours, mainly adenomas. Rational ways and recommendations for screening of hormonal activity of adrenal incidentalomas is discussed. Very important issue is to distinguish between benign and malignant lesions and between adenomas and non-adenomas. The accuracy of CT, MR, and fine needle aspiration cytology in distinguishing between adenomas from non-adenomas is comparable, in general not exceeding 90%. Particular characteristics of particular adrenal tumours are discussed. From the relationship between the tumour size and probability of malignancy, current recommendations are derived, that non-functioning tumours smaller than 4 cm are indicated for further follow-up, size over 6 cm is indication for adrenalectomy and in tumours between 4-6 cm decision process is complex.