The weird idea of ‘growing an extra ball’ is particularly common with spermatocele. This is because a hydrocele is as it were attached to the testicle, which as a result appears to grow bigger and bigger, while a spermatocele can be felt separately from the testicle, always at the level of the head of the epididymis. A weak spot may occur in the wall of the tubes between the testicle and the epididymis, a bulge develops and sperm cells accumulate in it. Such spermatoceles are very common: most middle-aged men have one or two. There are generally small, do not hurt and can do absolutely no harm. However, sometimes they grow to such proportions that it becomes difficult to go on walking with them. Anyone who consults a specialist and is told that an operation is proposed would be well advised to ask whether that operation is really necessary. There is a risk of damage to the artery to the testicle, inflammation and bleeding may occur, and moreover there is no guarantee that very shortly there will not be a recurrence of spermatocele. In order to prevent that the whole epididymis would have to be removed: with men who still want to have children it is completely disastrous to start operating.