The Authors report 4 cases very interesting for the differential diagnosis of phyllodes tumor, a breast tumor with a mainly local malignant potential. Such tumor, although presenting histologic, clinical and instrumental features which allow for a presumptive pre-surgical diagnosis, often has characteristics comparable to other breast pathologies with a different natural history. The Authors, after analyzing clinical, mammographic, echographic and histologic features of the tumor, suggest the most appropriate therapy for the local control of the lesion. Surgical excision should be carried at least 1 cm deep into the normal tissue to prevent local relapse related to an incomplete enucleation: in fact, the tumor is only apparently capsulated. Furthermore, the Authors believe a patients must undergo, after primary surgery, an adequate instrumental and clinical follow up for the early diagnosis of commonly occurring relapses.