Concurrent osteoblastoma and aneurysmal bone cyst of the ethmoid sinus: case report.

A unique case of osteoblastoma and aneurysmal bone cyst of the ethmoid sinus is reported. A causal relationship may exist between the two entities. The computed tomography appearance consisted of a dense lesion with a thin sclerotic rim containing a low-attenuation center, causing ethmoid sinus enlargement. Similar radiologic appearances are seen with other less rare pathologies.