Chondroblastoma of the temporal bone.

Chondroblastomas are highly destructive tumors that are derived from immature cartilage cells. The occurrence of this tumor in the temporal bone or skull base is uncommon. Approximately 70 cases have previously been reported, several of which have involved the temporomandibular joint (TMJ). We report here the case of a 67-year-old woman who presented with right-sided mixed hearing loss, a right external auditory canal mass, ear fullness, otalgia, blood-stained otorrhea, and pain around the TMJ, associated with difficulty in opening the mouth. CT and MRI revealed a mass involving the TMJ, infratemporal fossa, and pterygopalatine fossa. The patient underwent tumor resection via an infratemporal fossa approach type B. Gross total tumor removal was achieved, with no facial nerve paralysis or other complications observed after surgery. No recurrence or residual tumors were observed on CT and MRI, even after 7.5 years of follow-up. We conclude that temporal bone chondroblastomas are extremely rare and aggressive, but the outcome after appropriate surgical treatment is favorable. From the review, it may be particularly important to deal with tumors that involve the TMJ, which could affect the long-term outcomes, as well as tumor recurrence.