-Case Reports-

Microtia with Coexistent Large External Auditory Canal Cholesteatoma: A Case Report

Takeshi Matsunobu^1,*, Hirotaka Suzuki¹, Naoko Sakuma¹, Ryuji Ohashi² and Kimihiro Okubo¹

¹Department of Otolaryngology-Head and Neck Surgery, Nippon Medical School, Tokyo, Japan
²Department of Integrated Diagnostic Pathology, Nippon Medical School, Tokyo, Japan
^*Present address: Department of Otolaryngology-Head and Neck Surgery, National Defense Medical College, Saitama, Japan

Microtia is a congenital disorder characterized by an anomaly in the auricle. It is often associated with atresia, stenosis, or obstruction of the external auditory canal. In cases of microtia, the incidence of a normal external auditory canal, congenital external auditory canal stenosis, and congenital complete closure of the external auditory canal (aural atresia) is reported to be 8%, 8%, and 84%, respectively. Congenital stenosis of the external auditory canal can sometimes be accompanied by intractable otorrhea and otalgia, raising the possibility of complications of external auditory canal cholesteatoma. Here, we report a case of an adult with microtia and external auditory canal stenosis who presented to our clinic with complaints of otalgia. A large external auditory canal cholesteatoma was found in the patient's left ear. Although cholesteatoma is common in cases of canal stenosis, its extensive spread within the temporal bone is quite rare. A temporal bone-targeted computed tomography scan revealed a soft tissue shadow in the left external auditory canal with distensible expansion and bony destruction in the upper, anterior, and posterior walls of the external auditory canal. In patients with microtia who experience severe aural pain, the possibility of latent extended cholesteatoma should be considered.

J Nippon Med Sch 2025; 92: 468-473

Keywords
external auditory canal, microtia, cholesteatoma

Correspondence to
Takeshi Matsunobu, MD, PhD, Department of Otolaryngology-Head and Neck Surgery, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan
takeshim0471@gmail.com

Received, September 9, 2024
Accepted, September 30, 2024