Breast - nonmalignant
Benign tumors / changes
Lactating adenoma of breast

Author: Hind Nassar, M.D. (see Authors page)

Revised: 8 August 2017, last major update April 2010

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

PubMed Search: Lactating adenoma [title] breast

Cite this page: Lactating adenoma of breast. PathologyOutlines.com website. http://pathologyoutlines.com/topic/breastlactatingadenoma.html. Accessed October 17th, 2017.
Definition / general
  • Well circumscribed mass, arising during or shortly after pregnancy, composed of cuboidal cells with actively secreting, closely packed glands
Epidemiology
  • Usually during or shortly after pregnancy
  • Most prevalent breast lesion in pregnant women and during postpartum period (puerperium)
Sites
  • May also develop in ectopic breast tissue in axilla, chest or vulva (along "milk line")
Etiology
  • May actually be a coalescence of hyperplastic lobules, not a true adenoma
  • May have common origin with tubular adenoma (Hum Pathol 1985;16:707)
Case reports
Gross description
  • Well circumscribed, lobulated, solitary or multiple, gray tan cut surface, frequent necrosis / infarction
Gross images

Images hosted on PathOut server:

Contributed by Dr. Mark R. Wick



Images hosted on other servers:

Well circumscribed mass

Small cysts

Microscopic (histologic) description
  • Cuboidal cells with actively secreting, closely packed glands
  • Resembles pregnancy-like (pseudolactational) changes
  • Resembles fibroadenoma or tubular adenoma with lactational change microscopically
Microscopic (histologic) images

Images hosted on PathOut server:

Contributed by Dr. Mark R. Wick



Images hosted on other servers:

Well circumscribed

Invasive carcinoma

Focus of hyperplasia

Actively secreting epithelial cells

Greatly expanded lobules

Apical cytoplasmic blebs


Lactating adenoma

Stroma and dilated ectatic glands - H&E


Infarcted lactating adenoma - A: edge of infarction, B: hemosiderin laden macrophages, C: peripheral fibrosis, D: viable tumor, E: capsule

Orderly arrangement of glands

Clear vacuolization

Cytology description
Cytology images

Images hosted on PathOut server:

FNAB, contributed by Dr. Mark R. Wick



Images hosted on other servers:

Increased lobular size

Cytoplasmic vacuoles and background foamy material

Differential diagnosis