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.
The typical case is the presence of a painless, firm, solitary, mobile, slowly growing lump in the breast of a woman of child-bearing years. In the male breast, fibroepithelial tumors are very rare, and are mostly phyllodes tumors. Exceptionally rare case reports exist of fibroadenomas in the male breast, however these cases may be associated with anti-androgen treatment.
Needle biopsy is often a reliable diagnostic investigation. Some fibroadenomas respond to treatment with ormeloxifene. Cryoablation of a fibroadenoma is a safe, effective and minimally-invasive alternative to open surgical removal. Ultrasound is non-invasive and relies on tissue heating to destroy fibroadenoma cells. Focused ultrasounds have been used to treat other benign tumors, such as fibroid disease in the uterus. They are the most common breast tumor in adolescent women. They also occur in a small number of post-menopausal women. Their incidence declines with increasing age, and, in general, they appear before the age of thirty years.