title: Fine needle aspiration cytology of papillary endothelial hyperplasia. A case report.
abstract: BACKGROUND
  Papillary endothelial hyperplasia is an intravascular or rarely extravascular proliferation of endothelial cells. It is considered an unusual form of thrombus organization.
  
  
  METHODS
  A 41-year-old, healthy male presented with a neck mass, which was aspirated. The cytomorphologic features were interpreted as consistent with squamous cell carcinoma. Subsequent workup failed to reveal a primary lesion, and the mass was surgically excised. Histopathology showed papillary endothelial hyperplasia associated with a hematoma. Immunocytochemical staining for factor VIII-related antigen on a destained, alcohol-fixed smear from the fine needle aspirate confirmed the endothelial nature of the cells.
  
  
  CONCLUSIONS
  A vascular lesion should be considered in a fine needle aspiration biopsy of a head and neck mass, in particular when the clinical features are not consistent with a metastatic malignancy. The absence of cytoplasmic orangeophilia and immunoreactivity for factor VIII-related antigen may be helpful in establishing the diagnosis.
authors.affiliation: Department of Pathology, Medical College of Wisconsin, Milwaukee, USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Novak
authors.forename: D J
authors.initials: DJ
authors.lastname: Ferguson
authors.forename: R A
authors.initials: RA
authors.lastname: Komorowski
mesh_terms: D000328:Adult; D001707:Biopsy, Needle; D003937:Diagnosis, Differential; D004730:Endothelium, Vascular / Q000473:pathology*; D006406:Hematoma / Q000473:pathology; D006801:Humans; D006965:Hyperplasia / Q000473:pathology; D007150:Immunohistochemistry; D008297:Male