Clinical Characteristics for 348 Patients with Adrenal Incidentaloma

BACKGROUND: Adrenal incidentaloma is an adrenal neoplasm frequently encountered in clinical practice for which detection rates have recently increased. We describe here the clinical characteristics of adrenal incidentalomas. METHODS: A retrospective study was performed examining the age, sex, location, size, function, and the histological findings for 348 patients with an adrenal mass discovered incidentally on computed tomography (CT) undertaken for health examination or nonadrenal disease from August 2005 to May 2012. RESULTS: Patients consisted of 156 males (44.8%) and 192 females (55.2%), aged between 20 and 86. Adrenal masses were most commonly found in patients in their sixth decade (32.5%). Regarding the location of the masses, 62.0% were found in the left adrenal gland, 30.2% were found in the right, and 7.8% were found bilaterally. Of all of the masses analyzed, 87.1% were 1 to 4 cm in size, and an adenoma-like appearance was the most common finding (75.3%) seen on CT scans. Hormonal analysis showed that 82.2% of the masses were nonfunctioning, 6.0% were diagnosed as subclinical Cushing's syndrome, 4.6% were aldosterone-producing adenomas, and 7.2% were pheochromocytomas. Adrenalectomy was performed in a total of 69 patients having adenoma (50.7%), pheochromocytoma (24.6%), and carcinoma (4.3%). CONCLUSION: The characteristics of benign, malignant, nonfunctional, and functional adrenal masses that were incidentally found at our hospital were similar to those presented in other studies.