Table 1. Histological Features of Lesions Confirmed by Pathology.
| Histologic Features | No. of Lesions |
|---|---|
| Benign | |
| Abscess or mastitis | 13 (8)* |
| Adenosis | 53 (33)* |
| Benign phyllodes tumor | 2 (1)* |
| Fibroadenoma | 72 (45)* |
| Fibroblastic proliferation | 7 (5)* |
| Intraductal papilloma | 7 (5)* |
| Normal mammary tissue | 5 (3)* |
| Total | 159 (100)* |
| Malignant | |
| Ductal carcinoma in situ | 8 (4)† |
| Invasive ductal carcinoma | 178 (85)† |
| Invasive lobular carcinoma | 14 (7)† |
| Mucinous carcinoma | 3 (1)† |
| Malignant phyllodes tumor | 3 (1)† |
| Neuroendocrine carcinoma | 1 (1)† |
| Invasive papillary carcinoma | 2 (1)† |
| Total | 209 (100)† |
Data are number of findings. *Numbers in parentheses are proportions of masses that were benign, †Numbers in parentheses are proportions of masses that were malignant.