Differential diagnostics of adrenal incidentalomas

Abstract

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.