[Molecular biology of incidentally diagnosed adrenal gland space-occupying lesion]

The incidentally detected adrenal mass is with a prevalence of 1% in the general population the most common pathological process of the adrenal gland. In more than 85% of the cases it is caused by benign adenomas of the adrenal cortex. These tumors have a monoclonal composition and are, therefore, caused by oncogenic mutations with consecutive clonal expansion of this cell clone. In contrast to adrenocortical carcinoma, in which mutations of the IGF II gene locus and the p53 tumor suppressor gene has been found, the oncogenes involved in the tumorigenesis of adrenal adenomas have not been identified yet. However, opposite to other endocrine tumors the receptor-cAMP-proteinkinase A signaling pathway is not involved in the pathogenesis of these tumors. Insulin may be an important growth factor of incidentally detected adrenal tumors. Heterozygote 21-hydroxylase deficiency, however, does not seem to play a major role in the tumorigenesis of adrenal incidentalomas.