title: Diagnostic cytopathology in type II angiosarcoma of the breast: a case report.
abstract: BACKGROUND
  The rare occurrence of angiosarcoma of the breast is reflected in limited descriptions of fine needle aspiration (FNA) cytomorphologic findings in this neoplasm. We present a case of angiosarcoma of the breast and discuss the pitfalls in diagnostic cytopathology that can potentially lead to incorrect diagnoses in such cases.
  
  
  METHODS
  A 45-year-old woman presented with a 2-year history of a right-sided breast mass. FNA cytology revealed a hypocellular smear composed of cohesive ductal epithelial cells; isolated or loosely arranged, round to spindle-shaped fibroblastlike cells; and projectile growths of round, oval and polygonal cells on loose tangles of connective tissue. The background was hemorrhagic, with scattered foam cells. The overall cytologic diagnosis was inconclusive but suggested phyllodes tumor (of borderline malignancy). Excisional biopsy was performed, followed by simple mastectomy. Histologic features were consistent with angiosarcoma, a diagnosis that was supported by immunohistochemical studies.
  
  
  CONCLUSIONS
  On FNA smear, 49.1% of isolated atypical cells were positive for the endothelial marker CD34; however, cytomorphologic appearance of these cells resembled that of CD34-negative active mesenchymal cells. Angiosarcoma rarely occurs in the breast, and a definitive diagnosis is difficult based on cytologic examination of hypocellular smears alone. However, the presence of atypical round, oval and polygonal cells on loose tangles of connective tissue, suggesting sheared vasculature, can be an important diagnostic feature.
authors.affiliation: Department of Pathology II, Kansai Medical University, Osaka, Japan. kiyozuka@takii.kmu.ac.jp
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Kiyozuka
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Koyama
authors.forename: Masashi
authors.initials: M
authors.lastname: Nakata
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Matsuyama
authors.forename: Yasuyoshi
authors.initials: Y
authors.lastname: Nikaido
authors.forename: Naoto
authors.initials: N
authors.lastname: Shimano
authors.forename: Airo
authors.initials: A
authors.lastname: Tsubura
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism; D044963:Biopsy, Fine-Needle; D001808:Blood Vessels / Q000473:pathology*; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D042783:Endothelial Cells / Q000473:pathology; D004847:Epithelial Cells / Q000473:pathology; D005260:Female; D005347:Fibroblasts / Q000473:pathology; D006394:Hemangiosarcoma / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D008279:Magnetic Resonance Imaging; D042361:Mammary Glands, Human / Q000098:blood supply* / Q000473:pathology*; D008327:Mammography; D008408:Mastectomy; D008875:Middle Aged; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor