Fibroadenoma

Fibroadenoma is the most common benign breast tumor, mostly in young women. It consists in two components (epithelial and fibroblastic), estrogen-dependent, slowly growing. Until recently, traditionally, fibroadenoma was considered to be a benign mixed tumor, but recent studies showed that only the fibroblastic component is neoplastic (being monoclonal), while the epithelial one is only reactive, non-neoplastic (being policlonal). The tumor is round or ovoid, elastic, and nodular, and has a smooth surface. The cut surface usually appears homogenous and firm, and is grey-white or tan in colour. The pericanalicular type (hard) has a whorly appearance with a complete capsule, while the intracanalicular type (soft) has an incomplete capsule.