Differential diagnostics of adrenal incidentalomas

We have analysed the results of radiological investigations (USI, CT, and MRT) involving 177 patients given surgical treatment at the Endocrinological Research Centre during 2006-2010. In addition, the study included measurement of cortisol levels in the dexamethasone suppression test, fractionated metanephrins, and the relationship between aldosterone levels and plasma rennin activity (in the patients presenting with arterial hypertension). Twenty two patients underwent tumour puncture. Seventy six (55.9%) of the 136 patients having incidentalomas were found to have no indications for the surgical intervention (because of the absence of hormonal activity and low malignancy potential of the neoplasm). The follow-up period averaged 24.9±19 months. The choice of indications for the surgical treatment should be based on the results of standardized hormonal studies and the determination of malignancy potential using the native CT density above 20 UH as the principal criterion. Differential diagnostics by USI, MRT, and descriptive CT is believed to be inadequate. USI may be applied as a highly specific method for the detection of cysts and myelolopomas. Native CT density should be taken into consideration for the interpretation of the results of fractionated metanephrin measurements. Diagnosis of pheochromocytoma is very unlikely in the patients presenting with low CT density. Puncture biopsy is indicated only when the presence of metastases in the adrenal glands is suspected.

adrenal incidentaloma, adrenal tumour, pheochromocytoma, adrenocortical cancer, subclinical hypercorticism, subclinical Cushing's syndrome, primary hyperaldosteronism, symptomatic arterial hypertension

1. Кузнецов Н.С., Бельцевич Д.Г., Гончаров Н.П., Кац Л.Е., Кация Г.В., Колесникова Г.С., Ильин А.В., Мельниченко Г.А. Повышение уровня метилированных производных катехоламинов - патогномоничный лабораторный признак феохромоцитомы. Пробл эндокринол 2007; 1: 33-36.

2. Cawood T.J., Hunt P.J., O'Shea D., Cole D., Soule S. Recommended evaluation of adrenal incidentalomas is costly, has high false-positive rates and confers a risk of fatal cancer that is similar to the risk of the adrenal lesion becoming malignant; time for a rethink? Literature review. Eur J Endocrinol 2009; 161: 513-527.

3. Funder J.W. et al. Guidelines for management of patients with primary aldosteronism. J Clin Endocrin Metab 2008.

4. Nieman L.K., Biller B.M.K., Findling J. W., Newell-Price J., Savage M.O., Stewart P.M., Montori V.M. The diagnosis of Cushing's syndrome: an endocrine society clinical practice guideline. J Clin Endocrin Metab 2008; 93: 5: 1526-1540.

5. Pacak K. et al. Pheochromocytoma: recommendations for clinical practice from the First International Symposium. J Endocrinol Metab 2007; 3: 2.

6. Young W.F.Jr. The incidentally discovered adrenal mass. N Engl J Med 2007; 356: 601-610.