growth, if any, of the lesion. A growth rate of less than sixteen percent per month in women under fifty years of age, and a growth rate of less than thirteen percent per month in women over fifty years of age have been published as safe growth rates for continued non-operative treatment and clinical observation. Some fibroadenomas respond to treatment with ormeloxifene. Fibroadenomas have not been shown to recur following complete excision or transform into phyllodes tumours following partial or incomplete excision. Non-invasive Surgical Interventions There are several non-invasive options for the treatment of fibroadenomas, including percutaneous radiofrequency ablation (RFA), cryoablation, and percutaneous microwave ablation. With the use of advanced medical imaging, these procedures do not require invasive surgery and have the potential for enhanced cosmetic results compared with conventional surgery. Cryoablation The FDA approved cryoablation of a fibroadenoma as a safe, effective, and minimally-invasive alternative to open surgical removal in 2001. During cryoablation, ultrasound imaging is used to guide a probe into the mass of breast tissue. Extremely cold temperatures are then used to destroy the abnormal cells, and over time the cells are reabsorbed into the body. The procedure can be performed as an outpatient surgery using local anesthesia, and leaves substantially less scarring than open surgical procedures and no breast tissue deformation. The American Society of Breast Surgeons recommends the following criteria to establish a patient as a candidate for cryoablation of a fibroadenoma: The lesion must be sonographically visible. The diagnosis of a fibroadenoma must be confirmed histologically. The lesion should be less than 4 cm in diameter. High Intensity Focused Ultrasound High Intensity Focused Ultrasound (HIFU) is a newer technique for the treatment of malignant and benign tumors of the breast and has shown promising results in the form of complete radiological removal of tumors. An ultrasound beam is focused on a target in the breast and leads to tissue death and protein degradation by raising the temperature in that area. Currently, the use of radiation is recommended in some cases, but HIFU in particular is not part of treatment guidelines. Further research into the usefulness of HIFU, specifically in fibroadenoma, is required before more widespread use of the technique in fibroadenoma. Epidemiology Of all breast tissue samples taken, fibroadenomas comprise about 50%, and this rate rises to 75% for tissue sample in women under the age of 20 years. Fibroadenomas are more frequent among