title: Sinonasal hemangiopericytoma.
abstract: Hemangiopericytoma (HPC) is a rare entity that is found in only 1% of vascular tumours. Only 5% of HPC are localized in the nasal cavity or paranasal sinuses. The exact incidence is not stated in the literature.
  
  
  METHODS
  A case of a 76-year-old female patient is presented. As she suffered from stroke a cranial CT was performed and the tumour of the paranasal sinuses was diagnosed incidentally. The patient had a history of paranasal sinus surgery under local anaesthesia twenty years ago. The former histological diagnosis was stated as "angiofibroma with signs of proliferation ". The histopathologic diagnosis after endonasal sinus surgery was primarily a neoplasia with spindle-shaped cell formation. Just additional immunocytochemistry revealed the finding of primitive mesenchymal cells. This confirmed the diagnosis of a hemangiopericytoma. The two years follow-up showed no signs and symptoms of recurrent tumour on endoscopic examination and CT scans.
  
  
  CONCLUSIONS
  Hemangiopericytoma is a rare endonasal or sinonasal tumour. Occasionally histological diagnosis is difficult. Its characteristics are marked cellularity, vascularity and a dense net of reticular fibres. The entity shows a considerable tendency to recurrence, malignant transformation and metastasizing. After complete sinonasal surgery a regular short term follow up is advisable.
authors.affiliation: CVK Charité Berlin, Department of Otorhinolaryngology, Head and Neck Surgery, Berlin, Germany. veit.hofmann@charite.de
authors.forename: V
authors.initials: V
authors.lastname: Hofmann
authors.forename: H J
authors.initials: HJ
authors.lastname: Holzhausen
authors.forename: S
authors.initials: S
authors.lastname: Koesling
authors.forename: S
authors.initials: S
authors.lastname: Knipping
mesh_terms: D000368:Aged; D005260:Female; D006393:Hemangiopericytoma / Q000473:pathology* / Q000601:surgery; D006801:Humans; D010255:Paranasal Sinus Neoplasms / Q000473:pathology* / Q000601:surgery; D014057:Tomography, X-Ray Computed