Abstract
We report a rare case of giant fibroadenoma growing rapidly during pregnancy, which was difficult to differentiate from phyllodes tumor. A 30-year-old woman visited a local doctor with a left breast tumor measuring 2.5 cm in diameter. Since the first vacuum-assisted biopsy demonstrated fibroadenoma, the decision was made to continue observation. A month later, she became pregnant and the tumor subsequently showed gradual enlargement. In the 8th month of pregnancy, she was referred to our hospital for surgical treatment, because the tumor had grown rapidly to 15 cm in diameter. Fibroadenoma was identified from the second vacuum-assisted biopsy. Ultrasonography showed a heterogeneous mass with a clear boundary. Magnetic resonance imaging revealed a lobulated tumor compressing normal mammary tissue inward, containing heterogeneous intensity and suggesting phyllodes tumor. We performed tumorectomy at 32 weeks of pregnancy after considering the gestational stage. Pathological examination revealed pericanalicular-type fibroadenoma. We report this case with a review of the literature.
