& so it grows......

Please can any one offer any advice or help?
I was diagnosed with a malignant brain tumour in 2005 of which I had lots of radiotherapy and then finally had it removed in jan 2008.
Over the last 6 months I have lost weight, my blood count is dropping (currently 8.4) and my left breast is getting larger.
I am only 5ft 2 and although i’m quite ample (34E/F) my left breast is now escaping from an H cup and is beginning to look quite sily under baggy jumpers (thank heavens for the colder weather). I’m beginning to think I need lead in my shoes to keep me upright!
I have been refered to the breast clinic who did an ultrasound and said it was just fat tissue (thankfully) but couldn’t offer any further advice. He didn’t think it was hormonal, nor does by endocrinologist. (My periods have been getting a lot lighter and shorter). I’m only 35 so i’m not expecting it to be the menopause just yet!
Any ideas/suggestions please?