Phyllodes Tumor of the Breast: Pathology, Histogenesis, Diagnosis, and Treatment.

Phyllodes tumor of the breast is histologically unique in that it is composed of epithelial and stromal components. The histogenesis of this disease has remained largely unknown but recently we have obtained interesting information through clonal analysis, and have been able to show a difference in the histogenesis between phyllodes tumor and fibroadenoma. Elucidation of histogenesis would difinitely improve our understanding of the biological behavior of this disease and also help to establish the most appropriate treatment strategy. The pathology, histogenesis, diagnosis, and treatment of phyllodes tumor are reviewed in this paper. Our hypothesis on the histogenesis of this disease is also presented.