A review of previous cases and relevant literature has resulted in the following characteristics being identified with regard to malignant cystic lesions of the prostate: uneven density or enhanced signal within the cyst; irregular cyst wall with nodules and thickening; multiple cysts or cystic-solid mixed masses, with septa and solid components showing enhanced signal; rapidly growing cysts or recurrent cysts and elevated PSA levels.6 This evidence concerns the gene KLK3 and cyst.