9020/1 Phyllodes tumor, borderline


Cystosarcoma phyllodes, NOS
Phyllodes tumor, NOS


ICD-O-3 topography code: C50

Phyllodes tumours constitute one of the two major categories of fibroepithelial tumours of the breast (the other being fibroadenomas). Fibroepithelial breast tumours are biphasic lesions composed of an epithelial and a mesenchymal (stromal) component. The latter is quantitatively predominant and determines the overall appearance of the lesion.

Borderline PT is diagnosed when the the tumour does not possess all the adverse histological characteristics found in malignant PTs. While borderline PTs have the potential for local recurrence, they usually do not metastasize.

See Phyllodes tumour for images and detailed discussion.