Paget disease of the nipple or Paget’s Breast Cancer, is an uncommon type of breast cancer which occurs in and around the nipple. Almost 95% of the people with Paget’s breast cancer have underlying breast cancer. However, this type of cancer accounts for less than 5% of all cancer. The cause of the Paget disease is still unknown, however two major theories have been framed for the development of this disease. One theory states that the cancer cells break off from the tumor within the breast and travel along the milk ducts towards the nipple. Another theory states that the cells from the skin of the nipple become Paget cells.