Jakša Škugor, MD
From the Department of Radiology, General Hospital Šibenik
The great majority of renal masses are found incidentally as a result of the use of ultrasonography (US), computed tomography (CT), and magnetic resonance (MR) imaging. Fortunately, most of these are simple renal cysts that can be easily diagnosed and do not require treatment. However, solid and complex cystic renal masses are also discovered. The Bosniak renal cyst classification is a system used worldwide in evaluating cystic renal masses. It is based on CT findings and enables a cystic mass to be classified into one of five groups (categories I, II, IIF, III, and IV).
The major question to be answered is whether the mass represents a surgical or nonsurgical lesion or, in some cases, if follow-up studies are necessary.
The most important criterion used in differentiating surgical from nonsurgical renal masses is the determination of enhancement In general, any enhancing solid mass in the kidney should be considered a renal neoplasm.
CT is currently the modality of choice for diagnosing and staging renal neoplasms. MR can be used as a problem-solving tool for the evaluation of renal anomalies.