Fibroadenoma of the breast is a benign tumor characterized by proliferation of both glandular and stromal elements.

Most often it appears before age 30 as a result of estrogenic hormonal excess. Usually the tumor is solitary, multiple tumors being rare. The tumor is mobile to adjacent structures: skin, muscle, lymph nodes.

Pathology

Macroscopically: The tumor is round, elastic, nodular, less than 4 cm and encapsulated (well circumscribed); on cut surface it is grey-white. Microscopically: The epithelial proliferation describes duct-like spaces surrounded by a fibroblastic stroma. The proliferated epithelium is typical. Depending on the amount and the relationship between these two components, there are two main histological features: intracanalicular and pericanalicular. Often, both types are found in the same tumor. Intracanalicular fibroadenoma: stromal proliferation predominates and compresses the ducts, which are irregular, reduced to slits. Pericanalicular fibroadenoma: fibrous stroma proliferates around the ductal spaces, so that they remain round or oval, on cross section. The basement membrane is intact. 1

External links

Photos at: Atlas of Pathology