[Phyllodes breast tumors: apropos 2 cases].

The observation of two cases of phyllode tumors of the breast, one benign and the other malignant, brought the Authors to focus the fundamental aspects of these neoplasias. The histologic coexistence of both epithelial and connectival components, a relative unpredictable clinical evolution, the high frequency of recurrences, the stromal hyperproduction and modifications as expression of malignancy, and the need for large excisions are the fundamental characteristics of these tumors, which are considered transitional forms between benignity and malignancy.