<prompt> Bosniak classification is for?Renal tuberculosisRenal cystsRCCVUR  <response>: The Bosniak classification system of renal cystic masses divides renal cystic masses into five categories based on imaging characteristics on contrast-enhanced CT. It is helpful in predicting a risk of malignancy and suggesting either follow up or treatment. Classification: Bosniak I -Simple cyst , imperceptible wall; Work up:nil; Percentage malignant: 0 Bosniak 2 - Minimally complex, a few thin 1 mm septa or thin calcifications thickness not measurable; non-enhancing high-attenuation due to proteinaceous or haemorrhagic contents renal lesions of less than 3 cm are also included in this category; these lesions are generally well marginated; Work-up: nil; Percentage malignant: 0 Bosniak 2F - Minimally complex, increased number of septa, minimally thickened with nodular or thick calcifications there may be perceived but not measurable enhancement of a hairline-thin smooth septa hyperdense cyst 3 cm diameter, mostly intrarenal less than 25 of wall visible; no enhancement; Requiring follow-up: needs ultrasoundCT follow up - no strict rules on the time frame but reasonable at 6 months; Percentage malignant: 5 Bosniak 3 - Indeterminate thick, nodular multiple septa or wall with measurable enhancement, hyperdense on CT; Work-up: paial nephrectomy or radiofrequency ablation in elderly or poor surgical candidates; Percentage malignant: 55 Bosniak 4 - Clearly malignant solid mass with a large cystic or a necrotic component; Treatment: paial or total nephrectomy; Percentage malignant: 100. 