title: Presence of spermatogonia in 47,XXY men with no spermatozoa recovered after testicular sperm extraction.
abstract: OBJECTIVE
  To evaluate the presence of spermatogonia in men diagnosed with Klinefelter syndrome (KS), in whom no testicular spermatozoa were recovered by testicular sperm extraction.
  
  
  METHODS
  Retrospective case series.
  
  
  METHODS
  University hospital.
  
  
  METHODS
  Testicular samples from 22 nonmosaic 47,XXY men, aged 24-43 years, with no spermatozoa at multiple biopsies.
  
  
  METHODS
  Paraffin-embedded testicular tissue was sectioned and stained with hematoxylin-eosin, and immunostainings were performed for both MAGE-A4 and vimentin.
  
  
  METHODS
  The presence of spermatogonia.
  
  
  RESULTS
  Massive fibrosis and hyalinization were observed in all men with KS. Spermatogonia were observed in 4 of 22 men with KS, with differentiation up to the spermatocyte level in 2 of them.
  
  
  CONCLUSIONS
  A few men with KS, having no spermatozoa after testicular sperm extraction, still had few spermatogonia. These patients may eventually benefit from in vitro maturation using spermatogonial stem cells. The adult KS population can thus be divided into three subgroups: one subgroup showing focal spermatogenesis, a second having spermatogonia, and a third group in which no germ cells can be recovered. Further research is necessary to unravel the mechanism leading to these different patterns in patients with KS.
authors.affiliation: Research Group Biology of Testis, Department of Embryology and Genetics, Vrije Universiteit Brussel, Brussels, Belgium. dorien.van.saen@vub.ac.be
authors.forename: Dorien
authors.initials: D
authors.lastname: Van Saen
authors.forename: Herman
authors.initials: H
authors.lastname: Tournaye
authors.forename: Ellen
authors.initials: E
authors.lastname: Goossens
mesh_terms: D000328:Adult; D000951:Antigens, Neoplasm / Q000032:analysis; D001530:Belgium; D015415:Biomarkers / Q000032:analysis; D001706:Biopsy; D006785:Hospitals, University; D006801:Humans; D007150:Immunohistochemistry; D007713:Klinefelter Syndrome / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D008297:Male; D009363:Neoplasm Proteins / Q000032:analysis; D016612:Paraffin Embedding; D012189:Retrospective Studies; D025064:Sex Chromosome Disorders / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D013076:Sperm Count; D053625:Sperm Retrieval; D013091:Spermatogenesis / Q000235:genetics; D013093:Spermatogonia / Q000737:chemistry / Q000473:pathology*; D013094:Spermatozoa / Q000737:chemistry / Q000473:pathology*; D014746:Vimentin / Q000032:analysis; D014997:XYY Karyotype / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D055815:Young Adult
chemical_list: D000951:Antigens, Neoplasm; D015415:Biomarkers; C095204:MAGEA4 protein, human; D009363:Neoplasm Proteins; D014746:Vimentin