Malignant phyllodes tumor with chondrosarcomatous differentiation: Report of a case with cytological presentation

Malignant phyllodes firmer is a rare breast tumor with neoplastic epithelia l and stromal components. The stromal component may show homologous and het erologous sarcomatous elements, including chondrosarcomatous and osteosarco matous differentiation. Because these rumors may present with an almost exc lusively sarcomatous component, it is important for the pathologist to incl ude this entity in the diagnostic considerations of fine-needle aspirations of breast neoplasms showing sarcomatous differentiation. Following surgica l excision, careful examination of the gross specimen and thorough sampling of the specimen is recommended before rendering a definitive histologic di agnosis. We describe the cytologic aim histologic findings in a case of mal ignant phyllodes tumor with sarcomatous overgrowth showing predominantly ch ondrosarcomatous differentiation. (C) 1999 Wiley-Liss, Inc.