**3. Natural history**

*Basic Principles and Practice in Surgery*

commonly, virilization [1, 2].

techniques

**2. Epidemiology**

side [2, 3].

(10–15%)

7.Cyst (5%)

3.Myelolipomas (6–8%)

4.Adrenal carcinomas (4–11%)

5.Metastatic lesions (3–10%)

6.Aldosteronomas (2–6%)

from this condition. It mainly focuses on:

cause, for instance, the Cushing's syndrome, primary aldosteronism, or, not so

1.Whether there is hormonal production by the tumor and the controlling

2.The malignancy risk and the staging for propaedeutic planning purposes

The frequency of adrenocortical tumor diagnosis has increased nowadays due to larger availability of image examination techniques, which makes it a relatively common clinical problem currently. Some studies claim a detection rate of 4% in all abdominal computer tomography [4]. Studies in series of autopsies identified that adrenal masses count less than 1% in individuals younger than 30 years of age and

Adrenocortical tumors are more common in white, obese, diabetic, and hypertensive individuals. These data might be biased, as elderly, white individuals constitute the groups that most frequently undergo image examinations. It is known that such tumors are rather uncommon in individuals under 50 years of age and are especially uncommon in children [2]. They are more common on the right

being cortisol the most common one, which may cause Cushing's syndrome [1].

In terms of hormonal production, even though most tumors are nonfunctioning, in up to 15% of cases, there might be a slightly increased production of certain hormones,

Around 10–15% of all tumors found are bilateral [2]. Bilateral functioning adrenocortical masses may be congenital adrenal hyperplasia due to a 21-hydroxylase deficiency, adrenal macronodular hyperplasia, or primary hyperaldosteronism [2]. The most common causes of bilateral nonfunctioning adrenal masses are metastases, infections (mycosis, tuberculosis), lymphomas, bleedings, amyloidosis, and,

In a decreasing order of occurrence, the adrenocortical tumor categories are:

2.Cortisol-producing adenomas (including subclinical Cushing's syndrome)

that the rate increases to 7% in those who were 70 or older [1, 2].

rather rarely, carcinoma and myelolipomas [1].

1.Nonfunctioning adenomas (43–75%)

8.Tuberculosis and lymphomas (3–8%)

This present chapter discusses the preoperative assessment of patients suffering

**44**

Natural history of adrenocortical tumors is still not completely known [1]. Some studies suggest that most incidentalomas remain within stable size for many years [2]. Long-term follow-up studies suggest that from 5 to 20% of cases involving tumors larger than 1 cm, there is an increase in adrenal mass after an average period of 4 years, regardless of the state of adrenal hormonal production [1]. The typical increase rate of an adrenocortical carcinoma exceeds 2 cm per year, with a survival expectation lower than 50% within 5 years [1, 2].

Occasionally, tumor reduction might be observed (3–4% of cases). Appearance of mass at the contralateral gland might also be noticed. Nonetheless, the risk of malignancy development is low (<1/1000) [1].

There is a risk that a nonfunctioning adenoma starts to produce some hormone during follow-up, especially if the mass is larger than 3 cm and mainly in the case of cortisol production. Prospective studies show a 0.3% risk of a subclinical Cushing's syndrome development and a 0.2% chance of it turning into a pheochromocytoma. After a 3- to 4-year follow-up, such risk reaches a plateau that is to say the possibility that it would turn into a functioning one is low. Therefore, repetition of screening for functioning is only prescribed during the first 5 years of follow-up [2].

For the reasons explained here, rather small nodules (smaller than 1 cm) with a benign tomographic aspect need not be further investigated by image, as the benignity chance is high, whereas the risk of growth is low [2].
