About five years ago i went to the Emengency deptartment for chest pains, they did a chest Xray and said everything was fine and sent me home with a RX for pantic attacks but they said to follow up with my Family doctor, so that is what i did. he looked at my chart did an exam and said that they found a mass behind my chest wall but they thought it was nothing and he did not think it was anything but he wanted to ensure that he did not grow any so he had me in for another CT scan with dye this time and said that it actually shrunk, and nothing to worry about, but now i notice that on my neck more towards my collar bone i have a buldge it's not a bump or lump, i can push on it and it causes no pain, is this somthing i should be worried about.
I went into hospital with chest pains back in April, they did a chest xray said everything looked fine and sent me home with ibuprofen...
2 weeks later i was back in A&E again still chest pain and vomiting and headaches, they found my blood pressure to be dangerously high so kept me in for a week...
I had a CT scan and it turned out i had a mass infront of my heart and one in my liver, i then had to go home and wait 2 weeks for biopsy results to come back, i got weaker and weaker and was very sick, i then went to the clinic for the results and it was Non Hodgkins Lymphoma.
I have now just finished 6 courses of chemotherapy (which was awful) and fingers crossed waiting for my next scan to see if it has all shrunk away.
I personally would advise you to get another scan if you can, any mass near your heart is not a good thing, and they certainly don't know if it's serious or not without taking a biopsy from the lump.
Good luck and do something about it now, especially if you don't feel well!