This system is more directly focused on the most appropriate management. These alternatives are broadly to ignore the cyst, schedule follow-up or perform a surgical excision of it. When a cyst shows discrepancy in severity across categories, it is the most worrisome feature that is used in deciding about management. There is no established rule regarding the follow-up frequency, but one possibility is after 6 months, which can later be doubled if unchanged. Recommended management Ignore Follow Excise Calcification * Small, smooth and liquid (moves to lowest point when changing position) Thick, nodular If radiodensity > 20 HU without radiocontrast * Sharp margin, 3 cm * poorly defined * heterogeneous * solid on ultrasound Septations Thin and smooth Slightly greater than hairline * thick * irregular * nodular Enhancement (increase with radiocontrast) 15 HU Multilocular If infection All others Nodularity Very small and nonenhancing All others Wall thickening If infection All others Peripelvic versus parapelvic cysts Non-contrast CT (at left) showing peripelvic fluid accumulations, which may be hydronephrosis. CT urography (at right) reveals non-dilated calyces and pelvises. The fluid accumulations are thus peripelvic cysts. Parapelvic cysts originate from around the kidney at the adjacent<unk>  parenchyma, and plunge into the<unk>  sinus. Peripelvic cysts are contained entirely within the<unk>  sinus, possibly related to dilated lymphatic channels. When viewed on CT in absence of contrast, they can mimic hydronephrosis. If symptomatic, they can be laparoscopically decorticated - removal of the outer layer or cortex.
Renal cyst
Renal medullary fibroma
Ectopic kidney
Glomerulonephrosis
Cystic nephroma
Renal oncocytoma
Hydronephrosis
Page kidney