I. Breast divided into about 18 lobes, each with its own duct

II. Cysts and fibroadenomas are lobular (not lobar) in origin

III. At puberty, estrogen stimulates duct development; progesterone stimulates dev. of acinii/lobules

IV. Montgomery's tubercules--supply lubricant for suckling

V. Conditions

  1. Plasma cell mastitis ("Mammary duct ectasia")--consists of fatty tissue blocking ducts; looks like bag of worms, after long time get scarring and retraction of nipple; predominance of plasma cells on hist. examination
  2. Fibroadenoma--lobular in origin; mobile; no capsule; typical histological appearance
  3. Fibrocystic change--exaggeration of monthly histol. changes of breast; very common. Starts with fine granular nodules, feels like "cobblestones"; later, coalesce into cysts, occ. "blue-domed"--filled with blue fluid
  1. *larger cysts more likely to be Ca*
  1. Mondor's dis.--thrombophlebitis of thoracoepigastric v.--cord can be felt, often retraction too; prob. traumatic in cause; can be mistaken for Ca
  2. Sclerosing adenosis--fibrosis displacing nl. glandular tissue; twice as likely to get breast Ca
  3. Fat necrosis--due to trauma; can present as a hard, Ca-like palpable nodule