Breast - nonmalignant
Neonatal breast

Author: Belinda Lategan, M.D. (see Authors page)

Revised: 21 July 2017, last major update May 2014

Copyright: (c) 2002-2017,, Inc.

PubMed Search: Neonatal breast [title]

Cite this page: Neonatal breast. website. Accessed September 25th, 2018.
Definition / general
  • Identical in males and females at birth
  • Nipple is small pit in center of thickened areola, becomes everted shortly after birth due to proliferation of mesenchyme underlying the areola
  • Breast enlargement (uni or bilateral) is present in up to 70% of neonates due to neonatal prolactin production, caused by falling levels of maternal estrogens; associated with production of "witch's milk" in males and females
  • Continued breast stimulation (squeezing or massaging breasts) may cause hypersecretory state to persist
  • Milk secretion: resembles colostrum; contains water, fat and cellular debris
Microscopic (histologic) description
  • Duct dilation without acini
Microscopic (histologic) images

Images hosted on PathOut server:

AFIP: neonatal breast ectasia with dilation of mammary ducts