Definition
- Benign intraductal proliferation of progenitor epithelial cells with varying degrees of solid or fenestrated growth
Features
- Usually incidental finding
- Proliferation of epithelial cells in ducts or lobules with ≥ 2 layers of cells
- Normal = 2 cell layers (epithelial & myoepithelial)
- Hyperplasia: ↑ed no. of layers ± ‘fenestrations’ within layers
Classification
- Classification: Ductal vs. Lobular ± Atypia
- Mild ductal hyperplasia
- Proliferation of more than two but less than four cell layers between basement layer and lumen, without cellular atypia
- Florid ductal hyperplasia
- Moderate or florid ductal hyperplasia is defined as an intraductal epithelial proliferation greater than four cell layers, usually enough to distend the ductule and bridge the lumen. Can have some atypia
- Atypical ductal hyperplasia
- Proliferation with atypia. Differentiated from low grade ductal carcinoma in situ by size (≤ 2 mm) or space occupied by clonal cells (≤ 2 spaces or only portion of involved space)
- Mild ductal hyperplasia
Management
- Hyperplasia - nil
- Hyperplasia with atypia - operative
RR of Cancer:
