I started getting cysts in my breasts at the same time as T1 was coming on slowly in the background, on the day I was diagnosed I coincidentally had another appt at the breast unit so I was running round the hospital all day dragging my new blood sugar monitor with me, up to diabetes, down to bloods, into breast clinic, back to diabetes, back to bloods... nightmare. I asked them if it was related, they said no; however, one website did say that women with T1 are more likely to get breast cysts. I have a colleague whose T1 friend is the same. Because I'd been diagnosed with T1 I opted out of having the new ones aspirated at that point due to my overwhelming nightmare with needles(!) so left them there, where they remain 7 months later. I've put on so much weight (went from 8.5st to 10st, 5ft8) that my breasts have gained lots of welcome fat, so I don't even notice them any more anyway. Breast cysts are not harmful and do not lead to cancer, but I always have them checked as during the time I've had them (over 2yrs) my mum's had a double mastectomy so it's always wise to be checked out.