Malignant phyllodes tumor with liposarcomatous components: a case report with cytological presentation.

Cytological and histological findings of a rare case of a malignant phyllodes tumor (with liposarcomatous components) of the breast are presented. The atypia of the stromal cells and naked nuclei in a lesion considered benign clinically and on imaging alerted us to the possibility of a phyllodes tumor, despite the low cellularity of the preoperative fine-needle aspiration smears. The excisional biopsy was histologically diagnosed as malignant phyllodes tumor with liposarcomatous components. Peculiar atypical cells with large, pale, transparent cytoplasm, or with intranuclear chromatolytic areas similar to intranuclear cytoplasmic inclusions, in addition to atypical lipoblasts revealed in imprint smears from the excised tumor, may be important for cytopathologists to achieve a definitive cytological diagnosis, and also to observe patients over long periods for recurrences and metastasis after surgery for this rare breast tumor. Copyright 2000 Wiley-Liss, Inc.