title: Inflammation of embryonic connective tissue in the middle ear spaces.
abstract: OBJECTIVE
  Persistent embryonic connective tissue has been considered to be a cause of chronic otitis media with effusion in neonates and of cholesteatoma in later life. As part of a study of pneumatization and resorption of embryonic connective tissue from the middle ear of pre- and postnatal infants, inflammatory processes of variable extents have been observed within the embryonic connective tissue. The aim of the present study was to characterize this inflammation and to detect patterns in its presence and distribution.
  
  
  METHODS
  Twenty fetal temporal bones obtained at 4-8 months of development and 31 temporal bones from children who died of sudden infant death syndrome aged < 1 year were studied to assess the inflammation within the middle ear cleft and specifically in the embryonic connective tissue.
  
  
  RESULTS
  Sixteen of 27 (59.3%) pre- and 10/31 (32.2%) postnatal specimens displayed a non-specific inflammatory lymphocytic infiltration without signs of bacterial infection or the presence of or reaction to amniotic contents. Eleven of 27 prenatal temporal bones (40.7%) and 16/31 (51.6%) postnatal specimens showed no evidence of histologic middle ear inflammation. The presence or absence of inflammation was independent of age.
  
  
  CONCLUSIONS
  Our observations indicate resorption of the embryonic connective tissue with individual variations indicating that genetic factors are responsible for the development of the middle ear spaces during the phases of development studied.
authors.affiliation: ENT Department, Hospital Clinic, University of Barcelona, Barcelona, Spain. mbernal@clinic.ub.es
authors.forename: Manuel
authors.initials: M
authors.lastname: Bernal-Sprekelsen
authors.forename: Gerd
authors.initials: G
authors.lastname: Borkowski
authors.forename: Holger
authors.initials: H
authors.lastname: Sudhoff
authors.forename: Henning
authors.initials: H
authors.lastname: Hildmann
mesh_terms: D000208:Acute Disease; D002102:Cadaver; D003238:Connective Tissue / Q000002:abnormalities*; D004432:Ear, Middle / Q000002:abnormalities*; D005333:Fetus / Q000002:abnormalities*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007249:Inflammation; D010034:Otitis Media with Effusion / Q000196:embryology* / Q000473:pathology*; D013398:Sudden Infant Death; D013701:Temporal Bone / Q000002:abnormalities