Congenital anomalies of the eustachian tube in Down syndrome. Histopathologic case report.

Congenital anomalies of the eustachian tube (ET) that may play an important role in the cause of otitis media with effusion should be investigated histopathologically. One such anomaly, which has not been thoroughly investigated to date, is that accompanying Down syndrome. This report describes histopathologic findings in a temporal bone obtained from a 26-weeks' gestation male fetus with Down syndrome. As compared to a control specimen, its ET was extremely small, mostly collapsed in the midcartilaginous, isthmus, and tympanic portions, and had poorly developed lateral cartilage in the midcartilaginous portion. This is the first case report of such ET anomalies, which appear to be due to an insult to the ET that occurs earlier in fetal life than the 16th gestational week. This insult is possibly a causative factor in postnatal ET dysfunction.