Granulomatous orbital lesions: computed tomographic features.

Orbital lesions exhibiting granulomatous inflammation represent a heterogeneous group of diseases characterized by infiltration with epithelioid cells. The authors retrospectively reviewed the orbital computed tomography (CT) scans of 39 patients who had biopsy-proven lesions with granulomatous inflammation and found that diagnosis on the basis of CT was possible in only a few patients, those with a lesion of characteristic location and attenuation (such as a dermoid cyst) or characteristic distribution (such as bilateral enlargement of the lacrimal gland occurring in orbital sarcoidosis). In patients with multicompartmental disease exhibiting bone and extraorbital involvement the site of origin of the mass, the pattern of bone involvement and the clinical findings helped in classifying the cause of the lesion as Wegener's granulomatosis, a foreign body or mucormycosis. CT was crucial in determining the intraorbital and extraorbital extent of the lesion before excision or biopsy.