Temporal bone chondroblastoma: Imaging characteristics with pathologic correlation

Background Chondroblastoma commonly involves the temporal bone in the craniofacial region, but its imaging features have not been elucidated. This study aimed to describe the imaging features of temporal bone chondroblastoma with their pathologic correlation. Methods Radiopathologic correlation was performed in 5 patients with temporal bone chondroblastoma from our database and in 11 patients identified through a PubMed search. Results The cases of temporal bone chondroblastoma commonly involve the squamous part, temporal and infratemporal fossae, temporomandibular joint, and tympanic cavity, with the following features: high attenuation with calcification; heterogeneity; low signal intensity on T2-weighted imaging with enhancement; a smooth interface to the brain; and strong hypermetabolism on fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT. The heterogeneous low signal intensity on T2-weighted imaging was correlated with various histopathologic components, including calcification and hemosiderin deposition. Conclusion Temporal bone chondroblastoma usually forms as an expansile, heterogeneous, hypermetabolic mass in the middle cranial fossa, frequently with low signal intensity on T2-weighted imaging, reflecting various degrees of calcification and hemosiderin deposition.