title: Malignant phyllodes tumor metastatic to the lung with osteogenic differentiation diagnosed on fine needle aspiration biopsy. A case report.
abstract: 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.
authors.affiliation: Department of Anatomical Pathology, Royal North Shore Hospital, Pacific Highway, St. Leonards, 2065, Sydney, Australia. catrionamckenzie@iprimus.com.au
authors.forename: Catriona A
authors.initials: CA
authors.lastname: McKenzie
authors.forename: Jeanette
authors.initials: J
authors.lastname: Philips
mesh_terms: 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*