Non-aldosterone cortical adrenal adenomas
Non aldosterone secreting cortical tumours (NACA) represent the commonest benign adrenal tumour. These may be truly non-functioning, that is not associated with any hormonal excess and are usually detected co-incidentally in patients undergoing radiological investigations (ultrasound, CT, MRI scanning) for other reasons. Indeed autopsy studies have shown that up to 5% of the population may harbour so-called adrenal "incidentalomas". Malignancy rate in these lesions is very low - the majority of lesions are less than 3cm in diameter and can be treated conservatively.
Rarely the tumours may secrete cortisol. In the most florid example, Cushing's syndrome results because of severe hypercortisolism resulting in central adiposity, muscle wasting, thinning of the thin with bruising, osteoporosis, hypertension and diabetes mellitus. Removal of the adenoma is required to cure the condition. More rarely patients may have a genetic problem that results in autonomous production of cortisol from adenomas within the adrenals (e.g. McCune Albright syndrome or Carney's complex). The adrenals may also become hyperplastic or tumorous when the adrenal glands develop an unusual pattern of receptor expression over and above the normal receptor that controls cortisol production - the ACTH-receptor.
Less than 100 cases worldwide have been reported where the adenoma secretes only androgens. These androgen secreting tumours frequently present in women with increased facial hair growth (hirsutism), irregular periods and infertility sometimes with masculinization. It is a very rare cause of polycytic ovary syndrome.
"Sub-clinical" cushing's syndrome can also be found in patients harbouring adrenal incidentalomas occurring in up to 10% of all cases. These patients may have an increased risk of hypertension, obesity and diabetes.
In each a full and detailed assessment by an endocrinologist is required.