Cystosarcoma phyllodes tumors.

Of 106 females treated surgically for cystosarcoma phyllodes, 20 had one or more local recurrences, while seven other patients had "pseudorecurrences" in that the histologic findings showed benign disease of the breast. Histologic transformation into a histologically more aggressive lesion was noted in three patients. There was a higher incidence of recurrence among the younger patients (those less than 20 years of age) and in those with the larger tumors (greater than 5 centimeters diameter). The reasons for these findings are discussed. The phenomenon of recurrence was reviewed with regard to age of the patient, size of the lesion, histologic features of the tumor and extent of the operation.