Extraskeletal Chondroma in the Middle Ear: A Case Report

Extraskeletal chondroma, also known as soft tissue chondroma, is a benign cartilaginous tumor most commonly found in the hands and feet. The occurrence of extraskeletal chondroma in the external auditory canal is extremely rare. We report the first case of extraskeletal chondroma arising in the left middle ear. A 68-year-old female was referred to our department with a diagnosis of a left external - middle ear tumor accompanied by left-sided hearing loss. Otoscopic examination revealed a mass contacting the posterior surface of the anterosuperior quadrant of the tympanic membrane, protruding outward into the external ear canal. Computed tomography imaging demonstrated a soft tissue mass occupying the attic and tympanic cavity, extending into the external ear canal, without evidence of ossicular or bony erosion. The tumor was removed surgically using transcanal endoscopic ear surgery under general anesthesia. In addition to the prominent mass observed from the external ear canal, several smaller white and translucent tumors were identified deeper within the tympanic cavity and were meticulously removed individually. Careful monitoring may be appropriate in asymptomatic cases because malignant transformation of extraskeletal chondroma is rare. While recurrence of chondromas in the external auditory canal has not been reported, recurrence and malignant transformation have been observed in other anatomical sites. Therefore, long-term follow-up is necessary to monitor for potential recurrence or pathological progression.