**6. Adrenal image**

As previously mentioned, most adrenocortical tumors are benign, nonfunctioning adenomas that were incidentally found in abdominal image examinations such as computed tomography and abdomen magnetic resonance imaging.

Adrenal incidentalomas rarely have a malign cause in patients with no known record of cancer. It is estimated that only 2–5% of incidentalomas are formed by adrenal adenocarcinomas, and around 0.7–2.5% of cases are caused by metastasis from tumors elsewhere toward the adrenal [13, 14].

Size and some other radiology characteristics of the computed tomography and magnetic resonance imaging might help differentiating an adrenal benign lesion from a malign one, with consequent perioperative implications. Adrenal tumors with surgical indication are generally approached through laparoscopy. On the other hand, in cases when an adrenal adenocarcinoma is suspected, open surgery is preferable, especially for larger lesions (>10 cm), or for those that might expand to other organs [15].

There is a direct relationship between the size of the adrenal tumor and the potential for malignancy. Average size of an adrenal adenocarcinoma at diagnosis is 10–11 cm, whereas most benign adrenal tumors present a diameter smaller than 5 cm [16].

Besides their larger size, malign adrenal tumors, in most cases, show on image exams as heterogeneous lesions, with irregular margins, suggestive calcifications, and a peripheral enhancement by intravenous contrast due to the core of the necrosis. Expansion toward other organs and lymph node involvement confirm malignancy.

Adrenal adenomas feature a profuse presence of lipids in their constitution. It is, therefore, very useful to assess the lipid contents by means of density calculation for differentiating adrenal tumors [15].
