Fibroadenoma is the most common breast tumor in women. Malignant transformation occurs rarely within fibroadenoma atolder ages. Clinicians, radiologists, and pathologists need to beaware of malignant transformation within fibroadenomas. Radiologicstudies play an important role in the diagnosis of fibroadenoma;however, radiologic findings are often nonspecific formalignancy and may appear completely benign. We detected anoccult ductal carcinoma in situ that originated inside a fibroadenomaby using shear wave elastography. We report shearwave elastography findings of ductal carcinoma in situ withinfibroadenoma and discuss the diagnostic role of this modality.