Giant intracanalicular fibroadenoma is reported to be the most common cause of a massive, deforming enlargement of one breast in the female adolescent. It occurs infrequently and has a varied histopathologic pattern. It is suggested that obstetricians and gynecologists should have an awareness of this potentially malignant tumor of the breast with its associated problems of diagnosis and surgical management. Consideration of these huge breast tumors in relation to other similar breast lesions is presented in order to emphasize differential characteristics and treatment.