Giant solitary echinococcal cyst of the seminal vesicle: an uncommon cause of retention of urine.

Echinococcal cysts (EC) of the retroperitoneum are a rare occurrence. Such cysts involving the seminal vesicle and attaining massive size are very rare. These cysts may remain asymptomatic for long periods or may produce nonspecific symptoms. We herewith present a rare case of isolated giant EC of the seminal vesicle, which presented as acute retention of urine. To the author's knowledge, such a large EC of the seminal vesicle has not been reported previously in the medical literature.