Upgrade rate = rate at which a high-risk lesion on core biopsy is found to harbor adjacent malignancy (DCIS or invasive carcinoma) at surgical excision. Rates vary significantly by institution and patient selection.
High-Risk Lesion Management
| Lesion | Upgrade Rate to Malignancy | Management Recommendation |
|---|---|---|
| ADH (Atypical Ductal Hyperplasia) | 10–30% | Surgical excision recommended — high upgrade rate; cannot exclude adjacent DCIS on core biopsy |
| ALH (Atypical Lobular Hyperplasia) | ~5–10% | Excision vs. close surveillance (institution-dependent); excision if imaging-pathology discordant or if extensive on core |
| LCIS — Classic | ~1–2% per year (lifetime risk marker) | Surveillance + chemoprevention discussion; excision if discordant or mass-forming |
| LCIS — Pleomorphic | Higher than classic (approaches ADH rates) | Surgical excision recommended — behaves more aggressively; may co-exist with LCIS-type DCIS |
| FEA (Flat Epithelial Atypia) alone | ~5–10% | Observation vs. excision if isolated; excision if co-existing ADH or other atypia on same core |
| Papilloma without atypia | 3–7% | Observation vs. excision (institutional variation); excision if residual lesion on post-biopsy imaging or if solitary and peripheral |
| Papilloma with atypia | 15–30% | Surgical excision recommended — atypia substantially raises upgrade risk |
| Radial scar / Complex Sclerosing Lesion | ~7–10% | Surgical excision recommended — can harbor ADH, DCIS, or IDC within it; core biopsy may undersample the central nidus |
| Mucocele-like Lesion without atypia | <5% | Excision if imaging-pathology discordant or mass-forming; observation acceptable if concordant and completely sampled |
| Phyllodes Tumor (any grade) | Variable by grade (borderline ~10%, malignant ~25%) | Wide local excision with clear margins (1 cm for malignant); NO axillary dissection — hematogenous not lymphatic spread |
| Cellular Fibroepithelial Lesion | Cannot exclude phyllodes on core biopsy | Surgical excision — core cannot reliably distinguish fibroadenoma from phyllodes; full histologic assessment of stromal cellularity required |
ADH at core biopsy requires surgical excision at most institutions — the upgrade rate of 10–30% is too high for observation. Core biopsy samples only a portion of the lesion; adjacent DCIS can be missed.
Vacuum-assisted biopsy (VAB) and high-risk lesions: Larger-gauge VAB (9G, 10G) with complete radiologic removal of the target may reduce upgrade rates for some high-risk lesions (particularly papilloma without atypia, isolated FEA). If the imaging target is completely removed by VAB and pathology is concordant, some institutions may observe rather than excise — discuss with the referring surgeon and follow institutional protocol.