title: VHL gene deletion and enhanced VEGF gene expression detected in the stromal cells of retinal angioma.
abstract: OBJECTIVE
  Retinal angioma frequently occurs in von Hippel-Lindau (VHL) disease. However, VHL gene alterations have not been documented in retinal angiomas.
  
  
  METHODS
  Using tissue microdissection and polymerase chain reaction amplification, we have analyzed 7 retinal angiomas associated with VHL disease for loss of heterozygosity of the VHL gene. In addition, vascular endothelial growth factor expression was evaluated in these tumors by immunohistochemistry and in situ hybridization.
  
  
  RESULTS
  All 6 informative retinal angiomas showed loss of heterozygosity of the VHL gene. Loss of heterozygosity was detected in vacuolated "stromal" cells, but not in vascular cells or reactive glial tissue. Vascular endothelial growth factor protein and messenger RNA were also present in vacuolated "stromal" cells.
  
  
  CONCLUSIONS
  These findings suggest that vacuolated "stromal" cells represent the true neoplastic component in retinal angioma. These cells express vascular endothelial growth factor and therefore may be responsible for abundant neovascularization of retinal angioma.
mesh_terms: D000328:Adult; D016228:Endothelial Growth Factors / Q000235:genetics* / Q000378:metabolism; D017353:Gene Deletion; D015870:Gene Expression; D018324:Hemangioma, Capillary / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007124:Immunoenzyme Techniques; D017403:In Situ Hybridization; D008025:Ligases; D019656:Loss of Heterozygosity; D008222:Lymphokines / Q000235:genetics* / Q000378:metabolism; D008297:Male; D016133:Polymerase Chain Reaction; D011506:Proteins / Q000235:genetics* / Q000378:metabolism; D019572:Retinal Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D017154:Stromal Cells / Q000378:metabolism / Q000473:pathology; D025521:Tumor Suppressor Proteins; D044767:Ubiquitin-Protein Ligases; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D051794:Von Hippel-Lindau Tumor Suppressor Protein; D006623:von Hippel-Lindau Disease / Q000235:genetics*