Table 2.
Distribution of the subtypes of benign breast diagnoses
| Diagnosis | No. | % |
|---|---|---|
| Nonproliferative* | 32526 | 69.7% |
| Fibroadenoma | 8172 | 17.5% |
| Calcification | 9897 | 21.2% |
| Phyllodes tumor† | 108 | 0.2% |
| Other benign | 29256 | 62.7% |
| Proliferative disease without atypia | 11942 | 25.6% |
| Ductal hyperplasia‡ | 11942 | 25.6% |
| Atypical hyperplasia | 2179 | 4.7% |
| Atypical ductal hyperplasia | 1376 | 2.9% |
| Atypical lobular hyperplasia | 304 | 0.7% |
| Atypical ductal and lobular hyperplasia | 63 | 0.1% |
| Atypical hyperplasia, not otherwise specified | 436 | 0.9% |
| Total | 46647 | 100.0% |
* Women having biopsies with multiple subtypes are counted more than once in the table.
† Phyllodes tumor (coded historically as cystosarcoma phyllodes) may be malignant but is typically benign and has been included in the nonproliferative category; it has no association with epithelial carcinoma.
‡ Ductal hyperplasia includes usual ductal hyperplasia, complex fibroadenomas, sclerosing adenosis, and papillomas or papillomatosis. The clinical sites map these diagnoses to ductal hyperplasia prior to submitting data to the coordinating center, so no breakdown is available for presentation.