Abstract
Chondroblastoma is a rare benign bone tumor. It commonly affects the epiphysis
of long bones during the second and third decades of life. Chondroblastoma of
the temporal bone is extremely rare. We reviewed five cases of chondroblastoma
arising in the temporal bone. Four cases were female and one was male. The ages
ranged from 41 to 60 years (mean, 53.6 years). All cases involved the temporal
bone. Three involved the left side and two the right. Chief complaints were
long-standing localized pain and hearing difficulty. A sharply demarcated
lobulated mass was the main radiological finding. Microscopic findings were
those of chondroblastoma of usual locations. Two cases showed aneurysmal bone
cyst-like areas. Immunohistochemical studies for CD34, CD99, S-100 protein and
cytokeratin were performed. Tumor cells were diffusely positive for S-100
protein in three cases and weakly positive for cytokeratin in one case. CD34 and
CD99 were negative in all cases. In summary, chondroblastoma of the temporal
bone is rare and occurs in older age group than reported cases of
chondroblastoma of the usual location in the literature.