[A case of coexisting borderline phyllodes tumor and non-invasive ductal carcinoma].

A 36-year-old woman with benign phyllodes tumor of the left breast had undergone lumpectomy 1 year ago and was admitted to our hospital because of a left breast mass on the operation scar. Ultrasonography showed a 35 mm low-echoic, elliptical mass with a high depth to width( D/W) ratio in the C area and a 10 mm low-echoic, polygonal mass with a high D/W ratio in the E area. Histological examination of an ultrasonography-guided vacuum-assisted biopsy specimen indicated recurrent phyllodes tumor. Since both tumors were assumed to be recurrent phyllodes tumors, quadrantectomy was performed. Finally, the mass in the C area was diagnosed as a recurrent phyllodes tumor and the mass in the E area was diagnosed as a fibroadenoma. A non-invasive ductal carcinoma was incidentally detected between the 2 tumors, and the surgical margin was negative. Radiotherapy was performed on the remnant breast tissue.