I went to the Dr as I found two lumps in my breast. I was at the hospital two days later and, thank God, told I did not have cancer after the mammogram and I suppose a biopsy. The smaller lump has now disappeared, the larger one, which sounds like the one your wife has, in similar place has grown slightly and is sometimes painful. Dr told me it is a cyst and if it gets too big or painful I can have something done about it. I can't say this is what your wife has, obviously but I think if there had been a serious risk of cancer she would have had further tests straight away - they would not make her wait. I wish her, and you, well.