Worried about Hodgkins or Lung Cancer

Hi

 

A week ok I found a grape size lump above my right collar bone, went to my GP who referred for blood tests and a chest X Ray. Blood results came back all ok but just had a call to say they would like to do another X-ray to have another look at an 'area' in my right lung...up until today I thought if it was anything cancerous it would be Hodgkins but now they have said lung it's sent my head in a different way. I do smoke and I am 37 and although I do get coughs and a sore or achey chest now and then etc I don't think I have any 'symptoms'. I am sure there are plenty of non cancerous things it could be...any ideas? Many thanks!