Could The Wheezing And Breathlessness Be Due To The Lump Under The Nipple?

About 6 months ago I developed fatigue and wheezing. I am 67 with a history of cardiac problems. I was born with Fallot s Tetralogy which was corrected in 1964 in Bristol. It was very successful and I have had nearly 50 years of almost complete health, firstly as a teacher, and then as a vicar. I retired 2 years ago sadly because I had devloped an alcohol problem so I now live in care and haven t drunk since last August. When the wheezing began I automatically assumed it was due to a worsening of the residual faults from my Fallot s correction. I have lived with a small VSD, pulmonary stenosis and some atrial regurge. But having spent a week in hospital having echo tests , e.c.g, x-ray etc. the team failed to find any deterioration that would cause the things I am experiencing. A few weeks ago , however, I became aware of a hard lump under my right nipple. Not really painful but a bit sore. So I wonder if it s possible that I might have Male Breast cancer (however rare) and whether the wheeze, tightness of chest and breathlessness might be due to that. I don t want to bother my GP unnecessarily but on the other hand if it is a carcinogenic lump I would like to seek any treatment that might be available to me. Thank you. Rev. Robert Pitcher.