Seminal vesicle cyst associated with ipsilateral renal agenesis and papillary carcinoma of the bladder.

We report a case of seminal vesicle cyst associated with ipsilateral renal agenesis in a 37-year-old patient with papillary carcinoma of the bladder. Ultrasonography showed absence of the right kidney, a bladder tumour and a round retrovesical hypoechogenic mass with posterior acoustic enhancement. It showed low attenuation on CT, low signal intensity on T1-weighted MR images and high signal intensity on T2-weighted MR images. Intravenous urography (IVU) and cystoscopy were also performed. After surgery, it proved to be a seminal vesicle cyst. The embryology, imaging characteristics and differential diagnosis of seminal vesicle cysts are discussed. Associated findings are also described.