Idiopathic orbital inflammatory disease - a diagnostic dilemma.

Orbital pseudotumor is nonspecific orbital inflammation (NSOI). It is a benign, non-infectious, space-occupying inflammatory lesion of the orbit. NSOI can affect various tissues in the orbit, such as the lacrimal gland and extraocular muscles. The most common classification is based on clinical presentation. Bacteria, viruses, fungi, or parasites can cause infectious orbital inflammation. It is a diagnosis of exclusion after ruling out inflammatory, infectious, and neoplastic causes. We present a case of a male in his sixties who presented with progressive pain, swelling, blurry vision, and forward protrusion of his right eye. He had no history of trauma or recent illness. His general physical and systemic examination was within normal limits. His ocular examination showed eyelid edema, erythema, eccentric proptosis, and a mature cataract in his right eye. His left eye showed a lenticular opacity. CT orbit revealed a homogenous isodense lesion observed without any globe distortion. A diagnosis of orbital pseudotumor was made. The patient was treated with oral corticosteroids, and an excision biopsy was done, resulting in symptomatic improvement and regression of inflammation at follow-up. In complex cases of inflammatory orbital pseudotumor, particularly those with granulomatous inflammation, some initial success has occurred with monoclonal antibodies against tumor necrosis factor (TNF)-alpha or with lymphocyte depletion using rituximab. Our patient, however, responded well to an excision biopsy and a course of oral steroids.