Usually Paget's Disease affects just the nipple. If the doctor gave you some sort of cream for the eczema and it works, then that indicates that you don't have Paget's. Cancer doesn't respond to topical remedies. If the eczema doesn't get better, the doctor can do a biopsy to make sure it isn't cancer. If that lump is still there, you'll also need some follow up tests like an ultrasound to find out what it is. I hope you get good news.