Papillomas, atypical hyperplasias, and lobular carcinoma in situ of the breast are not malignant tumors, but present serious management challenges when they are diagnosed in a breast biopsy . Upgrading after excision and increased possibility of future cancer are risks that accompany these lesions. While some features have been defined as high-risk for upgrading, many practitioners now recommend conservative non-surgical treatment and vacuum-assisted biopsy . However, the challenge gets worse when the patient is pregnant or breastfeeding because of the limitations in imaging and treatment in relation to the fetus. This chapter deals with these problems, although the best management strategy cannot be defined because of lack of evidence at present.
Keywords: Atypical hyperplasia; Breast cancer; Lactation; Lobular carcinoma in situ; Papilloma; Pregnancy; Premalignant lesion.