Mammary cystosarcoma with mature adipose stromal differentiation (lipophyllodes tumor) arising in a lipomatous hamartoma
This report documents an uncommon variant of benign cystosarcoma phyllodes with mature adipose stromal differentiation, for which the term lipophyllodes tumor is proposed. Origin of this unusual tumor within a lipomatous hamartoma was confirmed by histologic and mammographic observations. The lesion developed in a 40-year-old woman 2 months post partum, and she remained well after treatment by biopsy. Lipophyllodes tumor, which features mature adipose tissue in much of the stromal component of a cystosarcoma, should not be mistaken for a malignant neoplasm. Complete excision is adequate therapy.