Giant juvenile fibroadenoma of the breast: a case report and brief literature review.

A girl (age, 12 years 11 months) consulted the pediatric endocrinology clinic because of a rapidly growing right breast mass over 13 cm observed during the preceding 3 months. A surgical excision was performed, and the mass was diagnosed as a giant juvenile fibroadenoma. Giant juvenile fibroadenomas are rare, usually occurring between 10 and 18 years of age, and characterized by massive and rapid enlargement of an encapsulated mass. The etiology is believed to be an end-organ hypersensitivity to normal levels of estrogen. We report a case of giant juvenile fibroadenoma and present a review of the diagnostic workup and management of a large breast tumor during adolescence.