Pre-operative Diagnosis of Invasive Ductal Carcinoma within a Fibroadenoma by Mammography

Fibroadenomas are the most common benign breast tumors, in which carcinoma rarely develop. We report the imaging findings of an invasive ductal carcinoma arising within the existing fibroadenoma in a 34-year-old young lady. It was diagnosed pre-operatively under suspicious mammographic findings and the malignant diagnosis was confirmed by excision biopsy. The mass showed an explosion of large popcorn-like calcifications with nests of fine pleomorphic calcifications therein, a lobular shape and an obscured margin. The calcifications in the mammogram correlated with histology so well to make the definitely pre-operative diagnosis possible. This case also reminds us that radiologists should always pay attention to the associated malignant imaging characteristics whenever a mass demonstrates typical benign looking calcifications. Correspondence Author to: Wen-Shih Kao Department of Medical Imaging, Chia-Yi Christian Hospital, Chiayi, Taiwan No. 539, Jhong-Siao Road, Chiayi 600, Taiwan J Radiol Sci 2011; 36: 105-108 preoperative diagnosis of breast carcinoma within a fibroadenoma 106 J Radiol Sci June 2011 Vol.36 No.2 Figure 2 Figure 2. Mammogram MLO a. and spot magnified CC view b. showed a 4cm lobular mass with intermediate density, an obscure margin and pleomorphic microcalcifications nested within popcorn like coarse calcifications in the right upper hemisphere. 2a 2b Figure 1. Sonography reveals an ovalshaped, wider than taller, circumscribed, heterogeneous hypoechoic mass with echogenic dots and dense posterior acoustic shadowing. Figure 1 preoperative diagnosis of breast carcinoma within a fibroadenoma 107 J Radiol Sci June 2011 Vol.36 No.2 a possible invasive component within an old fibroadenoma was made. The patient chose to have an excision open biopsy performed and the histopathology showed both in-situ and invasive ductal carcinoma in the background of a fibroadenoma. The carcinoma restricted itself dominantly to the involuting fibroadenoma (Fig. 3). Immuno-histochemical studies were positive for estrogen and progesterone receptors. After a modified radical mastectomy, the final pathologic staging was T2N0M0 by AJCC seventh edition. The patient’s course has been uneventful during two years of post-operative treatment.