[Chondroblastoma of the temporal bone--report of a case and a review of the literature of 54 cases].

Chondroblastoma of the skull is a rare tumor and only 54 cases have been reported to date. A case of chondroblastoma arising from the squamous part of the left temporal bone is reported. A 34-year-old woman had 6-month history of left conductive hearing disturbance and tenderness in the left temporal region. Plain skull X-ray showed a well demarcated osteolytic lesion in the temporal bone. CT demonstrated a heterogeneously high density mass, with enhancement. T1-weighted MRI showed a low intensity mass while T2-weighted images showed no signal area. The left external carotid angiograms showed a marked staining supplied by the left middle meningeal artery. This tumor grew destroying the left temporal squama and pyramidal bone, and extended to the external auditory canal and the middle ear cavity. The tumor was subtotally resected. Histologically, this tumor consisted of clusters of round or polygonal chondroblasts with oval or grooved nuclei and well-defined cell border. Multinucleated giant cells were also observed. Chondroid matrix was found in some areas. Immunohistochemically, the tumor cells were positive for S-100 protein. These findings lead us to the diagnosis of chondroblastoma. The diagnosis, histology, therapy, and prognosis of chondroblastoma are discussed including the review of 54 cases in the literature.