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

Abstract

Fibroadenoma is the most common benign tumor of the breast, and is very rarely associated with carcinoma. The prevalence of carcinoma within fibroadenomas in a screened population was reported to be 0.02% by Deschenes et al. (1). Buzanowski-Konakry et al. (2) identified 5 cases of carcinoma in a review of 4000 fibroadenomas examined over a 43-year period. The pathologic features of carcinomas within fibroadenomas were reported by Diaz et al. (3). Those authors evaluated 105 cases; in situ carcinoma was the predominant type of malignancy (95%) and lobular and ductal types occurred with equal frequency. Because ductal carcinoma in situ often forms microcalcifications consisting of dead and sloughed tumor cells within the ductal lumen, mammography can identify the pathology. We present a case of suspicious microcalcifications within a nodule identified on mammography, which correlated well with ductal carcinoma in situ within a fibroadenoma.