Endocrine Abstracts

Introduction: The prevalence of incidentally found adrenal tumors – adrenal incidentalomas (AI) – in imaging procedures and autopsy series is up to 4.5–8.7%. Endocrine and clinical evaluation is carried out to diagnose hormonal function or malignancy of the tumors. Nonfunctional adenomas comprise about 80% of AI. The aim of the study was to identify possible association between various clinical, hormonal and radiological features of nonfunctional AI.

Methods/design: We enrolled 100 patients aged 20–70 years with adrenal tumors discovered incidentally in computed tomography after ruling out possible hormonal function and radiological features of malignancy. We analyzed concentrations of many adrenal hormones. Overnight dexamethasone suppression test (DXM) was performed in the whole group and ACTH (Synacthen) stimulation test in 38 random subjects.

Results: The group consisted of 71% women and 29% men, 26% bilateral and 74% unilateral tumors. Prevalence of obesity, hypertension and diabetes were 32, 56 and 13% respectively. In bilateral tumors mean ACTH, DHEAS, basal 17-OH-progesterone (17OHP) were lower and DXM and stimulated 17OHP were higher than in unilateral lesions. There was a positive correlation between tumor size and DXM and stimulated 17-OHP and negative correlation with DHEAS. Furthermore DXM and stimulated 17-OHP increased with AI quantity. Cortisol was rising with age and decreasing with BMI. Women presented with higher basal 17OHP than men. Mean metanephrines were higher in hypertensive subjects.

Conclusion: Even AI defined as nonfunctional show some degree of autonomous cortisol secretion. In the adrenocortical tumor tissue different steps of steroidogenesis may be altered simultanously. Intratumoral cortisol overproduction and 21-hydroxyalse deficiency might be associated with tumorigenesis especially in development of bilateral, and multiple lesions as well as tumor growth. Catecholamines production may contribute to high incidence of hypertension in AI. Ageing and body mass should be considered in interpreting hormonal abnormalities in AI patients.