Abstract
A carcinoma arising in a fibroadenoma is a rare event, which often entails a diagnostic challenge. The most common type is the lobular carcinoma and secondary a ductal carcinoma.
We present an extremely rare case of malignant development of an invasive apocrine carcinoma in a complex fibroadenoma and underline the importance for clinicians to recognize the possibility of benign and malignant co-existence especially in older women.