Cystic renal lesions are a common finding in abdominal imaging.
Is essential for the radiologist to interpret properly their features with different techniques,
in order to ensure adequate patient´s management.
Different imaging techniques are used to evaluate cystic renal lesions: US,
CT and magnetic resonance (MR).
US has a high sensibility value in determining whether a detected cyst is simple or complicated,
in which case,
CT or MR imaging is required for further evaluation.
Bosniak´s classification categorizes each cystic renal lesion into five categories (I,
II,
IIF,
III,
IV) attending to CT imaging features.
It allows to predict the degree of complexity and likelihood of malignancy,
and suggests the following management: I and II cystic lesions do not need further evaluation,
IIF cystic lesions need follow-up and III and IV cystic lesions require surgical management.
Cystic renal lesions can be also classified as focal and multifocal (1).
We review the focal renal cystic disease including: sinus cyst,
pyelocalyceal diverticulum,
simple cyst,
complicated cyst,
pyogenic renal abscess,
mixed epithelial and stromal tumor (MEST),
cystic nephroma and cystic renal cell carcinoma.
On the other hand we review multifocal cystic renal disease categorized as hereditary,
acquired and developmental conditions.
A.
Acquired conditions include: Acquired cystic kidney disease and lithium-induced nephrotoxicity.
B.
Hereditary conditions include: Autosomal dominant polycystic kidney disease,
medullary cystic kidney disease,
Von- Hippel- Lindau disease (VHL) and tuberous sclerosis complex.
C.
Development conditions include: Glomerulocystic kidney disease (GCKD),
medullary sponge kidney (Cacchi-Ricci disease),
multicystic dysplastic kidney (MDK) and localized cystic renal disease.