Objective      To summarize the radiological manifestations and  our experiences on transurethral endoscopic treatment of giant seminal vesicle cyst

and analyze the pathogenesis

clinical and imaging characteristics

and corresponding diagnosis and treatment.       Methods      The clinical data of 7 cases of giant seminal vesicle cyst

including clinical symptoms

radiological images

transurethral endoscopic treatment procedure and postoperative follow-up

were retrospectively reviewed and analyzed.       Results      The images of computed tomography or magnetic resonance imaging (MRI) showed that the cysts were located behind the bladder and above the prostate and deviated from the midline in the pelvic cavity

with the size from 8.26 cm×7.98 cm×4.85 cm to 9.27 cm×8.95 cm×8.15 cm. Two cases of unilateral giant seminal vesicle cyst accompanied with ipsilateral renal and ureteral agenesis were supposed to be congenital malformation

and the other 5 cases showing simple giant seminal vesicle cyst were supposed to be caused by acquired ejaculatory duct obstruction. All the 7 cases of giant seminal vesicle cyst were successfully treated by transurethral endoscopic procedure including unroofing decompression and mucosa electrocautery. All the seminal vesicle cysts were confirmed by the pathological results

and no tumor was found. Postoperative follow-up showed that all the preoperative symptoms disappeared. Neither complication such as erection

ejaculation or orgasm dysfunction nor bladder or rectum injury was found. The seminal vesicle cysts were significantly decreased or disappeared in the postoperative 3-6 months.       Conclusion      MRI examination can clearly distinguish the cyst sources according to the cyst location and signal change

and offer an important guidance for the diagnosis and treatment of the pelvic cysts. Compared with the traditional open surgery and laparoscopic surgery

the transurethral unroofing decompression plus mucosa electrocautery is more minimally invasive

safe and reliable

and can be the first choice for the treatment of giant seminal vesicle cyst.