Ductal Carcinoma In Situ within a Fibroadenoma: Microcalcifications Identified on Mammography Play a Crucial Role in Diagnosis

Abstract

Fibroadenoma is a common, benign tumor of the breast, which is rarely associated with an increased risk of carcinoma. We report a case of ductal carcinoma in situ within a fibroadenoma in a 38-year-old woman. The lesion was a 1 cm, circumscribed, ovoid mass with internal calcifications evident on mammography and ultrasound, which is commonly found in fibroadenoma, but the calcifications were fine and linear, which is uncommon. This type of calcification is classified as suspicious by the American College of Radiology Breast Imaging-Reporting And Data System, and it is often correlated with comedo necrosis of ductal carcinoma, and, so, requires immediate pathologic confirmation. In our case, careful analysis of the unusual calcifications led to appropriate intervention and diagnosis. Radiologists should be aware that fibroadenomas can be malignant, and they should look for suspicious microcalcifications within a fibroadenoma.