Fibroadenomas are common in women of all ages, but we start seeing them as biopsies in younger, reproductive aged women. Often these are felt as breast lumps, and are brought to the attention of family physicians and OB-Gyns. These breast tumors are curious because they are formed from two elements unlike other breast lesions or breast disease. The fibroadenoma has both stromal and epithelial elements that are integral in its formation. Most of breast disease, in contrast, is formed by one element, and that is the epithelium or lining of the breast ducts.
Fibroadenomas have a fibrous stromal framework that surrounds slit like spaces lined by ductal epithelium. There are several variations of the epithelial growth pattern within the fibroadenoma, but always there are the two elements. In younger women the stroma is often looser and may have a bluish “juicy” appearance under the microscope. I often use the term “succulent” to describe these changes. As the fibroadenoma ages, the fibrous tissue becomes denser and calcifications may occur.
The fibroadenoma has a characteristic mammographic appearance, and the expert radiologist can often be sure of the diagnosis by its image characteristics. However, when there is any doubt about the exact diagnosis, a needle core biopsy is recommended. As you can imagine, until the lesion is sampled by a biopsy, you cannot be certain about the exact nature of the lesion that was felt originally, or found on mammogram. Biopsy of the lesion can bring relief from uncertainty, and allow for treatment decision planning based on facts.
As a general statement, fibroadenomas are benign and stay benign. These lesions may occur in sequence, meaning a new one may form after one has been removed. Both typically are very benign in appearance. Multiple fibroadenoma may occur at the same time in the same breast or both breasts. Only rarely is the fibroadenoma associated with malignant disease, but it does occur. The good news is that if this happens, the mammographic image changes, and needle core biopsy is recommended in this situation for diagnosis and clarification.
Treatment options are best discussed with your physician. In the majority of cases, the woman may decide to “live with” the fibroadenoma and leave it alone, or have it excised.