Results of Short-Term Follow-Up in BI-RADS 3 and 4a Breast Lesions with a Histological Diagnosis of Fibroadenoma at Percutaneous Needle Biopsy

OBJECTIVE: To evaluate the usefulness of short-term (6 months) follow-up in patients with Breast Imaging Report and Data System (BI-RADS) 3 and 4a lesions, after a diagnosis of fibroadenoma at an image-guided biopsy. PATIENTS AND METHODS: The data of 318 women with 349 biopsy-proven fibroadenomas, a 6-month follow-up, and a follow-up of ≥ 24 months were retrospectively reviewed. Information on clinical history, lesion characteristics on ultrasound (US), mammography, and magnetic resonance imaging (MRI), BI-RADS classification, and follow-up was collected. The false-negative (FN) rate and the negative predictive value (NPV) for the biopsy were calculated. RESULTS: 43 patients (13.5%) presented with a palpable nodule; 18 (5.7%) had a history of breast cancer. There were 334 lesions visible on US (95.7%), 57 on US and mammography (16.3%), and 15 on mammography only (4.3%); 37 lesions were first detected on MRI. All lesions were stable at 6 months. After an at least 1-year follow-up, 4 lesions changed their features and were excised. Histology showed 1 invasive lobular cancer, 1 ductal carcinoma in situ, 1 phyllodes tumor, and 1 papilloma. The FN rate of the needle biopsy was 1.1% and the NPV was 98.9%. CONCLUSION: For lesions initially described as BI-RADS 3 and 4a with a histological diagnosis of fibroadenoma after biopsy, short-term follow-up can be avoided.