| This is a low power view of a breast showing fibrosis (black arrow) separating ducts and lobules.
Some ducts are dilated and contain inspissated secretions (yellow arrows).
Another duct shows more than two cell layers within the lumen (blue arrows) consistent with proliferation.
It is not possible to tell at this power if this is typical, atypical or neoplastic intraductal proliferation. |
| Duct Hyperplasia (Non-atypical) |
| Etiology |
Secondary to an irregular response by breast tissue to hormonal stimuli |
| Pathogenesis |
May be due to relative or absolute excess of estrogen, decrease in progesterone, or abnormal response to either hormone by breast tissue |
| Epidemiology |
Reproductive age women |
| Clinical |
Found either by mammography or incidentally In the absence of atypia increased relative risk of developing breast carcinoma is 1.5-2 fold |
| General Gross Description |
May be associated with microcalcifications within the lumens Gross findings may be of fibrocystic change |
| General Micro Description |
Ducts exhibit more than the usual two layer epithelium (inner cuboidal to columnar cells; outer layer of myoepithelium) May be a solid mass of cells filling the ducts May show papillary infoldings (with fibrovascular cores termed papillomatosis) Maintain intact myoepithelial layer Slit-like spaces between cells Cells retain orientation toward lumen and/or slits Microcalcifications within ducts |
| Reference |
Robbins and Cotran: Pathologic Basis of Disease, 7th ed., 2005, pp. 1127-28.
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