Breast Physiology and Benign Diseases 2

Question 1

What is the nipple-areola complex?

Answer 1

• —The skin of the nipple contains sebaceous and apocrine glands
• —Smooth muscle bundles are interspersed between the ducts in the nipple
• —Nipple erection, emptying of milk from the ducts/sinuses when lactating
• —Areola has Montgomery’s glands/tubercles, smooth muscle fibers and peripheral hair follicles

Question 2

What are the features of basic breast hisology?

Answer 2

• —Constantly in flux, analogous to the endometrium
• —Basic histology:
  
  • ducts and lobules
  • epithelial (ductal) cells
  • myoepithelial cells
  • specialized stroma and fat
• —Most lesions including cancers arise from the so-called “terminal ductal lobular unit” or TDLU.
• —Majority of breast in resting state is stroma, proportion of which is fibrous or fatty varies, partly with age
• ——Size of mammary lobules, number of acini and appearance of epithelial cells is also variable:
  
  • —phase of menstrual cycle
  • inactive vs active (lactating) breast
  • age of woman

Question 3

What happens to breast histology during pregnancy and lactation?

Answer 3

• Number of lobules and number of acini within each lobule increase at the expense of intralobular and extralobular stroma
• Luminal epithelial cells with cytoplasmic vacuoles, often protruding into the lumen

Question 4

What are important features of post-menopausal breast tissue?

Answer 4

Postmenopausal breast consists largely of adipose tissue containing a few residual ducts and vessels.