Frontal Sinus Lesion

A woman in her 50s with a long history of allergic rhinitis was referred for progressive periorbital edema with proptosis of the left eye for the past 2 years, with associated nasal congestion, altered sense of smell, and intermittent left supraorbital pain. There was no associated history of diplopia or worsening visual acuity. She had not experienced facial trauma or sinus surgery. Treatment of allergic rhinitis with cetirizine and intranasal fluticasone had provided only partial relief. On examination, there was proptosis and periorbital edema of the left eye without any restriction of extraocular movements. The left supraorbital area was tender to palpation, with no abnormal masses appreciated. A computed tomographic (CT) scan demonstrated extensive thickening of the left frontal bone, extending over the entire roof of the orbit posteriorly (Figure, A and B). Changes within the frontal sinus were consistent with a soft-tissue component of the mass. Subsequent magnetic resonance imaging (MRI) (Figure, C and D) showed markedly hypertrophic bone in the frontal region and a homogeneously enhancing lesion within the left frontal sinus that was hyperintense on T2-weighted images, with left extraconal superior orbital and left frontal intracranial extension with dural enhancement. A combination above-and-below approach combining unilateral frontal sinusotomy with a trephination was performed. Abnormal tissue appearing in the left frontal sinus was removed, along with diseased tissue that extended into the orbital roof and orbit. Specimens were sent for pathologic evaluation, and findings demonstrated bony spaces containing lobules and whorls of spindle cells.