Cucumber - secondary growth

[sewer rat]

I noticed over the last couple of days that the lowest down cukes on some five or six of my plants seem to have a secondary growth appearing from half way down the cuke itself. This takes the form of what appears to be a new side shoot, and therefore renders the fruit unsaleable.
Anyone got any ideas as to what may be the cause and is there anything I can do to stop other fruits doing the same. I have removed the sprouting fruits and composted them

[zazen999]

haven't seen that one before - every one of my cukes seems to be a courgette at the moment; not sure what the heck is going on [I like courgettes but that't not the point]. They all seem to be the round courgettes as well, rather than the long ones. I had planted some of them, but never that many.
Serves me right for mixing my seeds - i wanted a surprise but not to the extent of losing a whole vegetable type.
Obviously have to do some emergency cuke sowing this weekend - whether it is a fruit day or not.