부신 Incidentaloma의 새로운 치료 경향 = New Treatment Trend of Adrenal Incidentaloma

다국어 초록 (Multilingual Abstract)

The prevalence of adrenal incidentalomas as discovered by ultrasound, CT scan and MRI are estimated to be 1 to 4.4%. The increasing occurrence of incidentally discovered benign adrenocortical tumors has become a clinical dilemma because of the difficulties in differentiating them from their malignant. Genetic alterations, such as LOH at the 17p13 and 11p15 loci and overexpression of the insulin-like growth factor-Ⅱ gene, are associated with the malignant phenotype in sporadic adrenocortical tumors. The most adrenal incidentalomas is benign and nonhypersecreting but all should be evaluated for hormonal activity and assessed for their risk of malignancy. Hormonal screening tests, including baseline cortisol and after dexamethasone, aldosterone-to-plasma renin activity ratio, DHEAS and catecholamines, are recommended to detect hypersecreting tumors. In all cases hormonal hypersecreting tumors(pheocromocytoma, hyperaldosteronism and subclinical hypercortisolism) should be removed. A difficult problem, however, is to distinguish between benign and malignant rimary or secondary tumors. Attenuation values on CT, chemical shift MRI, scintigraphy and FDG-PET reveal the nature of the mass in most cases. Radiologic evaluation by CT, MRI, scintigraphy and FDG-PET provide useful parameters toidentify malignant lesions. Size less than 4 ㎝ and an unenhanced CT attenuation under 10 HU are findings in favor of a benign adrenocortical adenomas. Norcholesterol and MIBG scans are able to detect benign tumors such as adenoma and pheochromocytoma, respectively. Conversely, FDG-PET allows for recognition of malignant adrenal lesions. Adrenalectomy is indicated for masses larger than 5 ㎝ in diameter or suspected of malignancy. Nonfunctioning cortical adenomas < 4 ㎝ size also should be followed clinically and radiographically. Laparoscopic adrenalectomy has been used increasingly as the preferred approach in patients who require surgical resection whereas open adrenalectomy is reserved for patients with > 6 ㎝ in size and malignant tumors. Fine needle aspiration biopsy should not be used routinely but reserved for cases suspected of other extra-adrenal malignancy.