Phyllodes tumours constitute 2-3 percent of fibroepithelial breast tumours, with a 1-2 percent rate of malignancy. Metastasis is usually haematogeneous, and axillary lymph node dissection is not routinely performed. Carcinoma in a phyllodes tumour is distinctly uncommon, but has been known to occur in benign phyllodes tumours. We describe a 51-year-old woman with a malignant phyllodes tumour with foci of intraductal carcinoma within the tumour and adjacent breast tissue. Though the carcinoma was found to be invasive based on the presence of carcinomatous lymph node metastasis, extensive sampling did not yield an invasive component within the breast, probably because of the marked stromal overgrowth of the phyllodes. A malignant phyllodes tumour with foci of intraductal carcinoma and axillary lymph node metastases was diagnosed rather than carcinosarcoma. Chemotherapy and irradiation were included in the postoperative management. Coexistence of phyllodes tumour and carcinoma is rare, and extensive sampling may be necessary to find the foci of carcinoma within an extensive and obviously malignant stromal overgrowth. There is little consensus on the treatment and prognosis in these cases, and it is recommended that treatment be tailored to individual patients, based on the presence of invasion, lymph node metastasis and/or distant metastasis.
Breast Breast Neoplasms