title: CD34-positive fibroblasts in Reinke's edema.
abstract: OBJECTIVE
  To elucidate whether and to what extent CD34+ fibroblasts (so-called CD34+ fibrocytes, CD34+ dendritic cells, and CD34+ stromal cells) occur in normal human vocal folds and in Reinke's edema.
  
  
  METHODS
  Histological study.
  
  
  METHODS
  Conventional, immunohistochemical, and ultrastructural procedures were performed in histological blocks of 18 selected cases of Reinke's edema (with typical findings including acellular edematous spaces in the subepithelial connective tissue of vocal folds, and disarrangement of elastic, collagen, and reticular fibers). For control purposes, four normal vocal folds were analyzed.
  
  
  RESULTS
  In normal vocal folds, most stromal cells were spindle-shaped CD34+ fibroblasts. In Reinke's edema, increased density and changes in the morphology and size of this subpopulation of fibroblasts were demonstrated in the connective tissue surrounding the edematous spaces, particularly in their borders, where together with some macrophages they formed boundaries, mimicking the walls of distended lymphatic vessels when conventional stains were used. These activated CD34+ fibroblasts acquired a dendritic morphology (with long, moniliform, often bifurcated, overlapping multipolar processes), and their cytoplasmic organelles were increased in number. In addition to CD34, they expressed vimentin, CD10 and CD99, but no α-smooth muscle actin (α-SMA), CD31, CD117, CD68, h-caldesmon, desmin, or S-100 protein.
  
  
  CONCLUSIONS
  CD34+ fibroblasts are a major cell component in the stroma of vocal folds in Reinke's edema, and their activation, with increased density and morphologic changes around the edematous spaces, occurs without immunophenotypic transformation toward myofibroblasts (no expression of α-SMA). The mechanisms by which these cells act in Reinke's edema require further study.
authors.affiliation: Department of Anatomy, Pathology, Histology, and Radiology , Faculty of Medicine, University of La Laguna, Tenerife, Spain.
authors.forename: Lucio
authors.initials: L
authors.lastname: Díaz-Flores
authors.forename: Ricardo
authors.initials: R
authors.lastname: Gutiérrez
authors.forename: María
authors.initials: M
authors.lastname: del Pino García
authors.forename: Hugo
authors.initials: H
authors.lastname: Álvarez-Argüelles
authors.forename: Lucio
authors.initials: L
authors.lastname: Díaz-Flores
authors.forename: Daniel
authors.initials: D
authors.lastname: López-Campos
mesh_terms: D018952:Antigens, CD34 / Q000276:immunology / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism; D001707:Biopsy, Needle; D016022:Case-Control Studies; D005347:Fibroblasts / Q000276:immunology / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D007819:Laryngeal Edema / Q000378:metabolism / Q000473:pathology*; D007820:Laryngeal Mucosa / Q000378:metabolism / Q000473:pathology*; D007828:Laryngoscopy / Q000379:methods; D012016:Reference Values; D016610:Tissue Embedding; D014827:Vocal Cords / Q000378:metabolism / Q000473:pathology
chemical_list: D018952:Antigens, CD34; D015415:Biomarkers
keywords: CD34 fibroblasts; Reinke's edema; vocal folds