Topic Outline
Topic Outline
Breast Biopsy
Topic Outline

Breast Biopsy

There is no contraindication to undergoing ultrasound- guided core needle breast biopsy, stereotactic core needle biopsy, or MRI-guided biopsy while breastfeeding, and there is no need to interrupt or stop breastfeeding before or after the procedure1.

Because the stereotactic and MRI-guided biopsies use a larger gauge needle2, removing more underlying parenchyma and producing a larger skin defect, the theoretical risk of milk fistula may be higher.  However, the risk of milk fistula remains very uncommon and is only documented in limited case reports in the literature3,4. A large cohort of pregnancy-associated breast cancer (PABC) patients demonstrated no milk fistula, even after surgical procedures5. We recommend uninterrupted breastfeeding after a biopsy to promote physiologic drainage through the nipple and away from the biopsy site. We do not recommend expressing and discarding milk with an electric pump, as this will stimulate supraphysiologic milk production and not provide physiologic removal of milk6. Temporary low-volume drainage lasting several days is normal and expected after a biopsy.  Milk may be blood-tinged, but is safe.

While lidocaine, a local anesthetic used during breast biopsy is considered safe with breastfeeding after intravenous, epidural, and high doses as a local anesthetic.  While there is no data on small volume injection used locally in the breast, it has poor oral absorption we do not feel that breastfeeding need be interrupted7. Epinephrine, a local anesthetic that may be used in conjunction with lidocaine, has no available data in breastfeeding.  However, it also has poor oral bioavailability and therefore is unlikely to necessitate interruption in breastfeeding8.


  1. Expert Panel on Breast Imaging, diFlorio-Alexander RM, Slanetz PJ, et al. ACR Appropriateness Criteria: Breast Imaging of Pregnant and Lactating Women. J Am Coll Radiol. 2018;15(11S):S263-S275.
  2. Hahn M, Okamgba S, Scheler P et al.  Vacuum-assisted breast biopsy:  a comparison of 11-gauge and 8-gauge needles in benign breast disease.  World J Surg Onc 2008;6:51.
  3. Schackmuth EM, Harlow CL, Norton LW. Milk fistula: a complication after core breast biopsy. AJR Am J Roentgenol. 1993;161(5):961-962.
  4. Barker P. Milk fistula: an unusual complication of breast biopsy. J R Coll Surg Edinb. 1988;33(2):106.
  5. Dominici LS, Kuerer HM, Babiera G, et al. Wound complications from surgery in pregnancy-associated breast cancer (PABC). Breast Dis. 2010;31(1):1-5.
  6. Lee SH.  Surgical management of enterocutaneous fistula.  Korean J Radiol 2012;13:S17-S20.
  7. Zeisler JA, Gaarder TD, De Mesquita SA.  Lidocaine excretion in breastmilk.  Drug Intell Clin Pharm 1986;20;691-3.
  8.  Accessed 11 Jan 2019.