Hello Professor_Wu and a big welcome to Cancer Chat, 

I think it is highly unlikely that they would have missed anything even if you felt the lump was a bit shy and the operator seemed to have trouble finding it. It's reassuring that the doctor told you the lump was just a vein but if you feel you would like to have reassurance as to whether they may have missed something, it might be worth giving your GP a call and asking them to explain things to you in further detail. You could take the opportunity to ask whether something could have been missed as you felt the operator was having trouble finding it. Talking to a doctor about it may give you peace of mind so don't hesitate to get in touch with them so that they can fully explain your results to you. 

Best wishes, 

Lucie, Cancer Chat Moderator