Common incidental urological lesions on computed tomography images: What to do with renal and adrenal computed...

The widespread use of cross-sectional imaging has led to the increased detection of urological incidentalomas. Incidental renal and adrenal masses are the most commonly detected urological incidentalomas and are often encountered by general practitioners.

This review aims to provide an evidence-based approach to managing renal and adrenal masses.

Renal lesions occur in 14% of computed tomography (CT) scans. Differentials include cysts (benign or malignant), angiomyolipomas, oncocytomas and renal cell carcinomas (RCCs). The Bosniak classification should be used for cystic renal lesions. Active treatment should be considered for RCCs that are >4 cm, symptomatic or rapidly growing. Patients with adrenal lesions should undergo functional work-up. If clinically concerned, screening tests include 1 mg overnight dexamethasone suppression test and plasma or urinary metanephrines. In the presence of hypertension or hypokalaemia, screening for hyperaldosteronism with the plasma aldosterone-to-plasma renin ratio should be considered. Benign adrenal adenomas on CT are <4 cm, homogenous and hypodense (Hounsfield unit <10).