Introduction:
Head and neck development involves morphogenesis with contributions from
the ectoderm, mesoderm, and endoderm layers, as well as neural crest
cells. During the fourth to sixth weeks of gestation, mesenchymal
proliferations known as hillocks of His arise from the first and second
pharyngeal arches. Under the influence of various molecular signals,
these hillocks undergo differentiation to give rise to structures of the
external ear, including the tragus, which arises from the first of the
six hillocks.1
Early in embryonic development, the preauricular sulcus emerges as a
remnant of the first branchial arch which initially appears as a skin
groove around the developing ear. As development continues, the
preauricular sulcus extends from its origin near the developing ear
towards the ventral aspect of the neck. Along its path, it passes
through the first pharyngeal cleft, eventually giving rise to structures
that eventually form part of the oropharynx. Abnormalities in this
migration process can occur, leading to the presence of ectopic tissue,
such as an accessory tragus, within the oropharynx.2,3
In this report, we discuss the case of an accessory tragus incidentally
identified in the oropharynx of a 20-year-old female presenting with
left-sided conductive hearing loss.