 [ Symptoms ] large lump on the base of the right testicle which comes and goes over the last year i have had three ultrasounds and each time i went to get the scans the lump was not present the ultrasounds did not detect anything apart from a minor varicocele previous to the last 2 months the lump would appear randomly even when i was not engaged in any sexual activity yet every time i went to see my gp it would not show itself  recently i have noticed the large lump usually appears when i am doing something sexual thanks [ Disease ] you could have a spermatocele and accumulation of sperm in the epididymis these may come and go less common would be epididymitis but this should be painful next time the lump appears make sure to have it examined while it is still there