Benign breast disease is a term used to describe a variety of breast changes that are prevalent in the population. This is unsurprising when the stimulatory nature of the menstrual cycle on breast tissue is considered. Benign changes are hugely varied and can be developmental, inflammatory, fibrocystic or neoplastic in nature. They are often proliferative but not atypical in nature. Most can be safely left without intervention once biopsy proven (Guray and Sahin [59]). The most common benign presentations are listed in Table 20.8, related to age. Breast cancer is, however, the most commonly diagnosed cancer amongst women in the UK with 54,800 cases diagnosed per year (Cancer Research UK [22]) and has a high media and social profile (Xu et al. [175]).