Factors associated with upgrading to malignancy at surgery of atypical ductal hyperplasia diagnosed on core biopsy

Previous studies have shown that 4-54% of breast lesions reported on core biopsies as atypical ductal hyperplasia (ADH) are upgraded on further excision to ductal carcinoma in situ (DCIS) or invasive carcinoma. We evaluated the rate of upgrading ADH to carcinoma at surgery for ADH diagnosed by percutaneous biopsy, and examined characteristics associated with malignancy. We identified 13,488 consecutive biopsies conducted at one center over a nine-year period. A total of 422 biopsies with ADH in 415 patients were included. DCIS or invasive carcinoma was found in 132 cases (31.3% upgrading). Multivariate model revealed that ipsilateral breast symptoms, mammographic lesion other than microcalcifications alone, 14G core needle biopsy, papilloma co-diagnosis, severe ADH and pathologists with lower volume of ADH diagnosis were factors statistically associated with malignancy. However, no subgroups were identified for safe clinical-only follow-up. Surgery is recommended in all cases of ADH diagnosed by percutaneous breast biopsy.