title: Vessel and Mast Cell Densities in Sporadic and Syndrome-associated Peripheral Nerve Sheath Tumors.
abstract: OBJECTIVE
  Peripheral nerve sheath (PNS) tumors constitute a heterogeneous group of solid tumors. Neurofibroma and schwannoma are the most frequently diagnosed entities. Both tumor types occur sporadically and are associated with syndromes. Current strategies to fight PNS progression by means of pharmaceuticals aim to specifically interfere with vascular growth factors identified in PNS. Furthermore, malignant transformation of PNS tumors is known to be associated with a change in vascularization. The aim of the study was to investigate vascularization of different PNS tumors with respect to sporadic or syndromal state of the entities.
  
  
  METHODS
  One hundred and thirty-two formalin-fixed and paraffin-embedded PNS tissue samples were retrieved from the archives of the Institute of Neuropathology, Eppendorf University Hospital. Lymphatic and blood vessels were immunohistochemically identified and morphometrically analyzed in PNS and controls.
  
  
  RESULTS
  Blood vessel density in malignant tumors was significantly higher than in benign lesions (30.8/mm(2) vs. 13.46/mm(2)). In the latter, the vessel density resembled that of control tissue. Lymphatic vessel supply was significantly higher in cutaneous neurofibroma and diffuse plexiform neurofibroma (PNF) than in intra-neural localized tumors (schwannoma, nodular PNF). Lymphatic vessels showed no marked differences with respect to tumor entity. Prevalence of mast cells differed markedly between tumor types.
  
  
  CONCLUSIONS
  Different vascularization of PNS may contribute to diverging tumor response following application of anti-neoplastic drugs. Mast cells may have an impact during formation and growth of neurofibroma but are unlikely to be involved in the process of de-differentiation.
authors.affiliation: Department of Oral and Craniomaxillofacial Surgery, University Medical Center Hamburg-Eppendorf, University of Hamburg, Hamburg, Germany rfriedrich@uke.de.
authors.forename: Reinhard E
authors.initials: RE
authors.lastname: Friedrich
authors.affiliation: Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, University of Hamburg, Hamburg, Germany.
authors.forename: Urs
authors.initials: U
authors.lastname: Naber
authors.affiliation: Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, University of Hamburg, Hamburg, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Glatzel
authors.affiliation: Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, University of Hamburg, Hamburg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Hagel
mesh_terms: D000328:Adult; D001808:Blood Vessels / Q000473:pathology*; D002452:Cell Count; D005260:Female; D006801:Humans; D042601:Lymphatic Vessels / Q000473:pathology; D008297:Male; D008407:Mast Cells / Q000473:pathology*; D018317:Nerve Sheath Neoplasms / Q000098:blood supply* / Q000473:pathology*; D009442:Neurilemmoma / Q000473:pathology; D009455:Neurofibroma / Q000473:pathology; D009456:Neurofibromatosis 1 / Q000175:diagnosis / Q000473:pathology; D013577:Syndrome
keywords: MPNST; NF1; NF2; Vessel density; blood vessels; lymphatic vessels; mast cell; neurofibromatosis; schwannoma; schwannomatosis