Hello,
Thanks for posting your query.

An epididymal cyst is usually an incidental finding and is a swelling which contains watery liquid and lies just above the testicle. An epididymal cyst is unlikely to be the cause of any erection problems or infertility except indirectly if it's painful when it becomez infected.

It does not cause infertility and you should be able to father a child. If it is causing any pain, then it can be treated by sclerotherapy of surgical excision.
You would need to see a physician immediately if the swelling increases in size or suddenly becomes painful.
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