A Histopathological Study of Congenital Atresia of the External Auditory Canal -A case report-

Abstract

Temporal bones from a case of congenital atresia of the external auditory canal were histologically studied and reported. A 14 days old female infant died of aspiration pneumonia following upper respiratory distress due to marked hypoplasia of the mandibule. Malformations were found in the external as well as middle ears. The right external ear canal was occluded by a bony atresia plate which was a part of the squamous or tympanic bone. The canal of the left ear was filled with fibrous connective tissue. The middle ear anomalies included hypoplastic epitympanum, absence of the cochleariform process, anomalous course of the tensor tympani musle, misshaped malleus and incus, missing lenticular process, fixation of the short process of the incus, bony fusion of the malleus with the medial wall of the tympanic cavity, foot plate fixation and persistent stapedial artery.
The bony and membranous labyrinths appeared normal, except the presence of the cyst-like structures in the crista of the left anterior and posterior ampullae and concretion in the base of the stria vascularis. The findings may be indicaticative of genetic disorder of the inner ear.