A Case of Invasive Ductal Carcinoma within Fibroadenoma

Abstract

A 40-year-old woman was diagnosed with fibroadenoma 10 years prior by her primary care physician. She visited our hospital because she had been aware of an increasing mass in the left breast and breast pain for several years. Ultrasonography revealed a 25-mm mass with abundant blood flow in region A of the left breast. Needle biopsy revealed fibroadenoma ; however, malignancy could not be ruled out. Therefore, partial mastectomy was performed with a 1-cm margin from the mass. The postoperative pathological diagnosis was invasive ductal carcinoma of the breast, ER-positive, PgR-positive, HER2 : 1+, and MIB-1 positivity : <1%). We herein report a rare case of invasive ductal carcinoma within a fibroadenoma.