The problem of incidentally detected bilateral adrenal tumors (incidentaloma) can be examined in several different ways. First of all, if such lesions are found, an „oncological vigilance” is obligatory as they might be bilateral neoplastic metastases (1). A quick differential diagnosis of metastatic lesions is possible by means of CT examinations during which the so-called imaging phenotype of tumors is assessed. Malignant lesions are characterized by a high coefficient of X-ray attenuation (density) prior to the administration of contrast medium and a low absolute and relative coefficients of contrast washout (which indicates a slow washout of the contrast medium in practice). Lipids are not found in such lesions on MRI (the assessment consists in comparing in-phase and antiphase signals produced by the tumor) (2, 3). A lack of lipids in the tumors might also give rise to suspicion of bilateral phaeochromocytomas – the presence of such lesions can be expected in patients with multiple endocrine neoplasia syndrome, whereas they are almost never present in other patients (4). Thus, it can be summarized that a detection of tumors containing no lipids in both adrenal glands is a definite indication for surgery after carrying out extended diagnostics (imaging examinations for detection of primary lesion in case of metastasis, a determination of 24-hour urinary catecholamines/metoxycatecholamines excretion, a MIBG scintigraphy and examinations for detection of other endocrinopathies in case of suspected phaeochromocytomas).

In case of bilateral adrenal incidentalomas, an assessment of their hormonal function is the second direction of actions. An excessive production of all the three groups of adrenocortical hormones (glucocorticoids, mineralocorticoids, androgens) and its autonomization may occur. In case of unilateral adrenal adenomas that show a subclinical hormonal function, the decision to perform surgery is usually taken. Adenomas can also occur as bilateral tumors with benign imaging phenotype, but they develop more often in the course of ACTH-independent macronodular adrenal hyperplasia (AIMAH) than in the case of unilateral lesions. A suspicion of hyperplasia changes the management method in case of detection of autonomous aldosterone production: a unilateral adenoma that causes a Conn’s syndrome is an indication for surgery, but a bilateral hyperplasia should be treated pharmacologically (5, 6). In case of hyperandrogenism with bilateral adrenal enlargement (with or without tumors) one may suspect an undiagnosed so far unclassical form of congenital adrenal cortical hyperplasia or hyperplasia of the reticular zone, which are also not an indication for operative treatment. Subclinical hypercortisolemia was for many years a definite indication for adrenalectomy (7, 8). However, recently arguments for a more cautious approach when making decisions on this operation were provided as it, even with an evident autonomization and increased cortisol secretion, does not always bring about a clinical improvement (9-11). The cases below from a large group of patients with bilateral adrenal tumors treated and observed in our teaching hospital department are illustrative of this problem.

A 66-year-old woman with overweight (BMI 29 kg/m²), hyperinsulinism diagnosed during OGTT, poorly controlled arterial hypertension (> 140/90 mmHg, 5 antihypertensive drugs) and hyperlipidemia has been admitted to the Teaching Hospital Department of Endocrinology of the Centre of Postgraduate Medical Education because of bilateral adrenal tumors detected during an abdominal cavity ultrasonography. An imaging assessment was carried out and the following lesions were visualized on abdominal CT: a lesion 32 x 30 mm in size in the left adrenal gland and a lesion 21 x 11 mm in size in the right adrenal gland that had a density of +4 Hounsfield units (HU) and from -1 to +1 HU, respectively (fig. 1). A normal renin/aldosteron ratio (RAA), a normal concentration of adrenal androgens, normal both cortisol concentrations and circadian rhythm of cortisol excretion with a low morning ACTH concentration of 5 pg/ml were found in the hormonal evaluation. A lack of cortisol suppression (4.8 μg/dl) was found in the test performed with a dexamethasone (1 mg dose). In order to confirm the diagnosis of secretion autonomization and identify the secreting side, a radio-labelled norcholesterol (NP-59) scintigraphy of the adrenal glands was carried out and a predominant radiotracer uptake in the left adrenal gland was found (fig. 2). In consideration of the diagnosed autonomous hormonal function, the female patient has been approved for a laparoscopic removal of the left adrenal gland. A macronodular adrenocortical hyperplasia was found during a histopathological examination of the tumor. After the operative procedure, the female patient required substitutive doses of hydrocortisone for half a year due to the insufficiency of the other adrenal gland (during the 2^nd month after surgery, the morning concentration of cortisol was 6.1 μg/dl, ACTH 2 pg/ml and 17-OHCS 2.1 mg in 24-hour urine collection), which definitely confirmed the preoperative diagnosis of subclinical hypercortisolemia. During the first six months after surgery, a decrease in body mass occured (down to BMI 23 kg/m²), the control of arterial pressure improved, which enabled a reduction of the doses of hypotensive drugs (at present, she is treated with sartan and a calcium channel blocker). The concentration of triglycerides, cholesterol-LDL fraction decreased.