Auricular ossification resulting in external auditory canal stenosis.

Abstract

We report the case of a 49-year-old man who presented with left aural fullness, hearing loss, and a stenotic left external auditory meatus. Physical examination and computed tomography revealed the presence of an idiopathic ossification of the cartilaginous auricle and external auditory canal. The patient was successfully treated with meatoplasty. Pathologic examination of the removed specimen revealed osseous metaplasia.

Introduction

The petrified auricle is a rare clinical entity in which all or part or the auricle becomes immobile as a result of ectopic calcification or ossification. The process of petrification can be initiated by local injury secondary to frostbite, physical trauma, or an inflammatory or systemic disease. The difference between ossification and calcification of the auricular cartilage cannot be ascertained clinically; the distinction can be made only by histologic evaluation. (1) Calcification is the more common cause.

Auricular ossification may be bilateral or unilateral, and it is more common in males. We report a case of auricular ossification in a man who presented with left aural fullness, conductive hearing loss, and a stenotic left external auditory meatus.

Case report

A 49-year-old man presented with left aural fullness and a 15-dB hearing loss. He denied otalgia and otorrhea and a history of frostbite or trauma. The remainder of his medical history was unremarkable, and he took no medications.

On examination, both auricles were immobile and had a firm, bony consistency, but only the left auricle was symptomatic. The left external auditory meatus was stenotic and almost completely occluded. Computed tomography (CT) of the left temporalbone demonstrated that the density of the auricular cartilage was similar to that of bone (figure 1).

The patient underwent meatoplasty. During the procedure, he was found to have ossification of the external auditory meatus. The ossification was removed with a drill and rongeur. Pathologic examination revealed a bony deposition in the auricular cartilage (figure 2).

Postoperatively, the conductive component of the patient's hearing loss improved. The ear canal was patent and able to be cleaned. The contralateral ear remained asymptomatic.

Discussion

Auricular ossification is for the most part asymptomatic, although some patients report discomfort at night secondary to pressure on the pinna during sleep. Patients may experience a gradual stiffening of the pinna over time. Examination of the pinna will reveal that the rigidity does not involve the earlobe. Radiographic evaluation will show an increase in the density of the auricular cartilage that is consistent with ossification or calcium deposition.

The process of ectopic ossification begins with the production of bone morphogenetic protein, which leads to the release of a cascade of mediators that results in the formation of bone? By contrast, calcification of otherwise normal tissue can be found throughout the body. Calcification can be initiated by deposition of the mineral in tissue that has been damaged by frostbite, mechanical trauma, and certain systemic conditions. Additionally, secondary calcification can occur as a result of aberrations in calcium metabolism. Petrification of the auricles is caused more often by calcification than by ossification.

[FIGURE 1 OMITTED]

The most common cause of auricular ossification is severe frostbite. Hypothermia leads to thrombosis, ischemia, and a proliferation of lamellar bone. (3) Other local causes include recurrent exposure to cold without frostbite, repeated manipulation of the pinna, mechanical trauma, radiation therapy, acne scarring, and insect bites. Auricular ossification has also been associated with inflammatory conditions such as chondritis, perichondritis, and syphilitic perichondritis, as well as with neoplasms such as nevi of the face, pilomatrixoma, and chondroid syringoma. (4) Finally, many systemic diseases can lead to auricular ossification, including congenital plaque-like osteomatosis, Albright hereditary osteodystrophy, fibrodysplasia ossificans progressiva, Addison disease, osseous heteroplasia, and collagen vascular diseases, especially CREST syndrome and childhood dermatomyositis. (3)

Some systemic diseases have been associated with auricular calcification but not ectopic ossification. Among them are hypertension, alkaptonuria, systemic chondromalacia, relapsing polychondritis, and familial cold hypersensitivity. (4) Other systemic diseases associated with petrified auricles are scleroderma, acromegaly, diabetes mellitus, hypopituitarism, and hypothyroidism. (3) Our patient's disorder was idiopathic, as he had no history of inciting conditions.

[FIGURE 2 OMITTED]

There is little information regarding the treatment of this disorder. Wedge resection of a calcified auricle has been reported as a cure for insomnia? Our patient was successfully treated with meatoplasty to relieve stenosis of the external auditory canal secondary to ossification of the auricle and lateral meatus.

References

(1.) Strumia R, Lombardi AR, Altieri E. The petrified ear--a manifestation of dystrophic calcification. Dermatology 1997; 194(4):371-3.

(2.) DiBartolomeo JR. The petrified auricle: Comments on ossification, calcification and exostoses of the external ear. Laryngoscope 1985;95(5):566-76.

(3.) Stites PC, Boyd AS, Zic J. Auricular ossificans (ectopic ossification of the auricle). J Am Acad Dermatol 2003;49(1): 142-4.

(4.) Yeatman JM, Varigos GA. Auricular ossification. Australas J Dermatol 1998;39(4):268-70.

(5.) Lister GD. Ossification in the elastic cartilage of the ear. Br l Surg 1969;56(5):399-400.

Matthew J. Carfrae, MD; David Foyt, MD

From the Division of Otolaryngology, Department of Surgery, Albany (N.Y.) Medical College (Dr. Carfrae), and the Capital Region Ear Institute, Slingerlands, N.Y. (Dr. Foyt).

Corresponding author: David Foyt, M D, Capital Region Ear Institute, 1220 New Scotland Rd., Suite 301, Slingerlands, NY 12159. Phone: [phone]; fax: [phone]; e-mail: [e-mail]