Orbital Pseudotumor is defined as a benign, non infective, nonspecific inflammatory conditions of the orbit without identifiable local or systemic causes.

Idiopathic orbital inflammation has highly variable clinical features, from a diffuse to very focal process targeting specific orbital tissues, such as the lacrimal gland, extraocular muscles, optic nerve and orbital fat. Presentations vary according to the specific location and the degree of inflammation, fibrosis, and mass effect. Ptosis, chemosis, motility dysfunction, and optic neuropathy may also be found.  Unilateral presentation is typical, but bilateral presentations are not uncommon.

Idiopathic orbital inflammatory Syndrome

Radiological imaging studies allow tissue characterization and localization without surgical intervention and thereby have become invaluable diagnostic tools. Computed tomography is the preferred mode of imaging. Idiopathic orbital inflammation is typically seen on CT scans as a focal or diffuse mass, usually poorly demarcated and enhancing with contrast. Common CT findings include enhancement with contrast medium, infiltration of retrobulbar fat, proptosis, extraocular muscle enlargement, muscle tendon or sheath enlargement, apical fat edema, optic nerve thickening, uveal-scleral thickening, edema of the Tenon capsule, and lacrimal gland infiltration. Tendons of the extraocular muscles may be involved or spared.

The histopathological spectrum of idiopathic orbital inflammation is typically non diagnostic, wide, and diverse, ranging from the typical diffuse polymorphous infiltrate to the atypical granulomatous inflammation, tissue eosinophilia, and infiltrative sclerosis. In the absence of systemic fibro inflammatory, granulomatous, and vasculitic disease.