Chondroblastoma of the Temporal Bone: A Case Report and Review of the Literature

Introduction: Chondroblastomas occurs in 1% of primary benign bone tumors and those involving the temporal bone is extremely rare. Most of the cases occur in the petrous apex, affecting individuals, especially in the age range between 30 and 40 years. It may also show a malignant behavior with invasion of adjacent structures.

Objectives: This study aims to review temporal bone chondroblastomas based on a case report.

Resumed Report: A 44-year-old woman with no medical history, was referred to our institution with a 1 year long left hypoacusis and an external auditory canal mass associated with left facial palsy. The imaging studies demonstrated an expansive mass inside the left external auditory canal, with osteolysis, filling the entire tympanic cavity and the basal portion of the petrous apex of the temporal bone. Based on a tissue biopsy of the left external acoustic meatus mass, which suggested a possible chondroblastoma, the patient underwent a surgery (total petrosectomy) with resection of the tumor. The lesion was found to involve the facial nerve, which was resected along with the lesion. The temporal bone chondroblastoma was confirmed by histopathological analysis of the tumor.

Conclusion: The most frequent presentation of chondroblastoma involving the temporal bone is as a nontender mass with a variety of otologic complaints, including hearing impairment, tinnitus, and aural fullness. The diagnosis is usually missed because of its rarity, unusual site, and variable histology. According to the published literature the most effective modality of treatment appears to be total excision with or without radiation.

Keywords: Chondroblastoma, temporal bone, petrosectomy, ear.