title: How useful is the assessment of lymphatic vascular density in oral carcinoma prognosis?
abstract: BACKGROUND
  Lymphatic vessels are major routes for metastasis in head and neck squamous cell carcinoma (HNSCC), but lymphatic endothelial cells (LECs) are difficult to recognize in tumor histological sections. D2-40 stains podoplanin, a molecule expressed in LECs, however, the potential prognostic usefulness of this molecule is not completely understood in HNSCC. We aimed to investigate the value of assessing peritumoral and intratumoral lymphatic vessel density (LVD) as prognostic marker for HNSCC.
  
  
  METHODS
  Thirty-one cases of HNSCC were stained for D2-40 and CD31. LVD and blood vessel density (BVD) were assessed by counting positive reactions in 10 hotspot areas at x200 magnification.
  
  
  RESULTS
  D2-40 was specific for lymphatic vessels and did not stain blood vascular endothelial cells. LECs showed more tortuous and disorganized structure in intratumoral lymphatic vessels than in peritumoral ones. No statistical differences were observed between peritumoral-LVD and intratumoral-LVD or between peritumoral-BVD and intratumoral-BVD. Tumor D2-40 staining was positively associated with lymphatic vessel invasion (p = 0.011).
  
  
  CONCLUSIONS
  LVD is a powerful marker for HNSCC prognosis. We found significant differences in peritumoral and intratumoral D2-40 immunoreactivity, which could have important implications in future therapeutic strategies and outcome evaluation.
authors: Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Braga, Portugal. longatto@ecsaude.uminho.pt.
authors: Adhemar
authors: A
authors: Longatto Filho
authors: Tiago Gil
authors: TG
authors: Oliveira
authors: Céline
authors: C
authors: Pinheiro
authors: Marcos Brasilino
authors: MB
authors: de Carvalho
authors: Otávio Alberto
authors: OA
authors: Curioni
authors: Ana Maria da Cunha
authors: AM
authors: Mercante
authors: Fernando C
authors: FC
authors: Schmitt
authors: Gilka Jf
authors: GJ
authors: Gattás