Table 3.

Pathology identified on percutaneous breast biopsy

Benign proliferative change (B2)

Fibroadenoma

Fibrocystic change

Sclerosing adenosis

Columnar cell change

Indeterminate lesions (B3)

Atypical ductal proliferation (AEDIP)

In situ lobular neoplasia, including lobular carcinoma in situ and atypical lobular hyperplasia (ILN)

Papilloma

Radial scar

Mucinous lesions

Non-invasive cancer (B5a)

Ductal carcinoma in situ (DCIS) and intracystic carcinoma

Pleomorphic lobular carcinoma in situ

Invasive cancer (B5b)

Invasive ductal carcinoma

Invasive lobular carcinoma

Special type including papillary, tubular and mucinous carcinomas

AEDIP, typical epithelial ductal proliferation; DCIS, ductal carcinoma in situ.

Cancer which extends <1 mm outside the duct wall is classified as microinvasive (B5c).