What Causes A Cyst On The Testicles Which Is Causing Itching?

hi doctor, I am 29 years old.I have many gram size/less then pea size object appeared on my testicals some 10 years ago.Earlt,it was small size but with passage of time it grown up to peas sized.it dont have any mouth,no puss,no swelling.no bleeding just itching....I have consulted with the physician/surgeon they identified it as CYST..... I keep my that area clean and always wear cotton underwears.do change regularly but problem couldn t be solved..I had operated it once....surgeon only operted large ones but now smaller one s growing to become larger with passage of time........... please suggest any medicine to permenantly solve it