Cementoossifying fibroma of the paranasal sinuses: A review of two cases

Cementoossifying fibroma (COF) of the paranasal sinus is a rare benign fibroosseous tumour arising from the periodontal membrane. It contains multipotential cells capable of forming cementum, lamellar bone and fibrous tissue. Cementoossifying fibroma peaks in the third and fourth decades and occurs more frequently in women than in men. Occasionally COF may grow aggressively and extend to involve the orbits and skull base, resulting in serious cosmetic and functional problems. We present CT and magnetic resonance imaging (MRI) findings of two young adults with cementoosifying fibroma of the paranasal sinuses who presented with progressive proptosis and facial deformity. Previously unreported correlations with Cerebral Angiography and MR spectroscopy are discussed.