Atypical Ductal Hyperplasia of the Breast
Differential Diagnosis
Low Grade DCIS vs. Atypical Ductal Hyperplasia (ADH)
- Low grade DCIS requires all of the following
- Complete filling of ducts by cells with uniform round nuclei without substantial overlap
- No streaming of cells
- No columnar cell population
- Sharply punched out cribriform spaces, microacini or bulbous papillae
- Solid low grade DCIS is rare but must be excluded before using this feature to diagnose ADH
- Size over 2-3 mm and involvement of at least two ducts
- If any one of the above features are lacking, designate as ADH
| Low Grade Ductal Carcinoma In Situ and Atypical Ductal Hyperplasia | Columnar Cell Change / Hyperplasia |
|---|---|
| Architectural complexity manifested by a) partial or complete filling of ducts or b) arcades or micropapillary formations | Essentially a flat lesion, lacks architectural complexity |
| Low grade nuclear atypia present (except some cases of ADH that have architectural complexity) | Cytologically bland |
| Low Grade Ductal Carcinoma In Situ and Atypical Ductal Hyperplasia | Flat Epithelial Atypia |
|---|---|
| Architectural complexity manifested by a) partial or complete filling of ducts or b) arcades or micropapillary formations | Lacks architectural complexity |
