Invasive Lobular Carcinoma of the Breast Arising within a Fibroadenoma—A Case Report and Review of the Literature—

Abstract

We report a case of invasive lobular carcinoma (ILC) arising within a fibroadenoma (FA) in a 52-year-old woman with breast cancer. The patient had been diagnosed as having a 17-mm FA in the upper inner quadrant of the left breast by a fine needle aspiration biopsy 12 years earlier. Recently she presented with an uncomfortable feeling in her left breast and was diagnosed with right breast cancer. Increased blood-flow within the known FA albeit with no morphological change on ultrasonography was observed, and needle biopsy confirmed a diagnosis of ILC within the FA. She underwent bilateral partial mastectomy and right axillary lymph node dissection. The pathological examination revealed a 7-mm ILC within the 12-mm FA in her left breast and breast cancer in the right breast (pT1bN1M0 Stage IA). Although breast cancer arising within a benign FA is rare, FA with any unusual imaging findings may require further examination. Here, we discuss the diagnostic strategies of breast cancer arising within a FA, a rare and challenging condition, based on the review of previously reported cases in Japan.