Benign Breast Disease
Maternal Medical Conditions Benign Breast Disease

Benign Breast Disease

While there is a paucity of information regarding breastfeeding in the setting of benign breast disease, breastfeeding generally is possible and successful.  Non-proliferative benign breast disease that affects women of childbearing age includes but is not limited to fibroepithelial lesions, hamartomas, cysts, and idiopathic granulomatous mastitis (IGM).  Proliferative breast disease, both with atypia and without atypia, may also present in the breastfeeding population.  An example of proliferative breast disease without atypia is a radial scar or complex sclerosing lesion, while an example of a proliferative disease with atypia is atypical ductal hyperplasia (ADH)1.

While these lesions themselves do not preclude breastfeeding, some women with atypia may be recommended to use endocrine therapy (e.g. tamoxifen, a Selective Estrogen Receptor Modulator, or SERM) to reduce future risk of breast cancer development.  SERM’s are known to inhibit lactogenesis II.  There is no data regarding transfer into breastmilk and therefore they are not recommended during breastfeeding2. We recommend nuanced discussion with the medical care team regarding the benefit of SERM’s versus the risk-reducing benefits of breastfeeding, which is most significant in those women with a first-degree relative with breast cancer3 and those with a BRCA I mutation4.

It should be noted that if a mass is in close proximity to the nipple areolar complex prior to pregnancy, it may present a challenge with breastfeeding if it interferes with latch or obstructs the retroareolar region.  Therefore, we recommend these patients be referred for evaluation by a breast surgeon and breastfeeding medicine specialist to determine whether the risk of removal and potential damage to underlying parenchyma, lymphatics, and neurovascular structures outweighs the risk of the mass itself causing a significant breastfeeding complication5. If the patient does undergo surgical excision, she should be referred to lactation during pregnancy and be monitored closely in the postpartum period for any assistance needed with breastfeeding.


  1. Dyrstad SW, Yan Y, Fowler AM, Colditz GA.  Breast cancer risk associated with benign breast disease:  a systematic review and meta-analysis.  Breast Cancer Research and Treatment 2015;149: 569-575.
  2. Masala A, Delitala G, Lo Dico G et al.  Inhibition of prolactin release after mechanical breast stimulation in women given tamoxifen or placebo.  Br J Obstet gynaecol 1978;85:134-7.
  3. Steube AM, Willett WC Xue F et al.  Lactation and incidence of pre-menopausal breast cancer:  a longitudinal study.  Arch Intern Med 2009;169:1364-1571
  4. Kotsopoulos J, Lubinski J, Salmena L et al.  Breastfeeding and the risk of breast cancer in BRCA I and BRCA II mutation carriers.  Breast Cancer Res. 2012;14:R42.
  5. Ferre R, Pare M, and Mesurolle B.  Ultrasound features of retroareolar breast carcinoma 2017;98:409-413.