A case of unilateral virginal breast hypertrophy with a review of the etiol
ogical factors and treatment modalities is presented. A 16-year-old girl pr
esented with progressive enlargement of the left breast of 5 months' durati
on. The result of the mammographic examination was consistent with cystosar
coma phyllodes, Fine-needle aspiration biopsy revealed giant fibroadenoma,
A[though some of the characteristics of the fine-needle aspiration biopsy s
pecimen were suspicious for cystosarcoma phyllodes, there were no adequate
epithelial structures, which are obligatory for the diagnosis. The patient
was treated with subcutaneous mastectomy and subpectoral insertion of a sil
icone gel implant. The histopathological examination was consistent with vi
rginal hypertrophy. The breast maintained its volume with no further growth
in the affected or in the normal breast after 4 years of follow-up.