Malignant phyllodes tumor metastatic to the lung with osteogenic differentiation diagnosed on fine needle aspiration biopsy. A case report.
BACKGROUND
Osteosarcomatous differentiation in malignant phyllodes tumors is rare. No cases of either primary or metastatic lesions were identified in the literature that were initially diagnosed on fine needle aspiration biopsy.


METHODS
Cytologic and histologic findings of a metastatic malignant phyllodes tumor with osteosarcomatous differentiation in a 63-year-old woman are presented. This case was diagnosed initially on fine needle aspiration biopsy and confirmed with histologic examination of the pulmonary lesion.


CONCLUSIONS
Although rare, the differential diagnosis of metastatic phyllodes tumor should be considered in the appropriate clinical setting when examining a pleomorphic spindle cell tumor with heterologous elements on fine needle aspiration biopsy.
McKenzie
Catriona A
CA
Department of Anatomical Pathology, Royal North Shore Hospital, Pacific Highway, St. Leonards, 2065, Sydney, Australia. catrionamckenzie@iprimus.com.au
Philips
Jeanette
J
D001707:Biopsy, Needle; D001943:Breast Neoplasms / Q000473:pathology*; D002454:Cell Differentiation; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology* / Q000503:physiopathology / Q000556:secondary; D008875:Middle Aged; D009362:Neoplasm Metastasis / Q000473:pathology; D010012:Osteogenesis; D003557:Phyllodes Tumor / Q000473:pathology*