Idiopathic orbital inflammatory pseudotumor: case report and review of the literature.

Idiopathic orbital inflammatory pseudotumor is a chronic neoplasm-like inflammatory reaction, usually affecting the orbital tissues of both eyes and orbit. Isolated optic nerve involvement by the idiopathic inflammatory process is a rare finding and very few reports are available. Here a case of an isolated orbital nerve inflammatory pseudotumor presenting with gradually progressive unilateral loss of vision is described. It showed dramatic response to surgery and steroid treatment and its differential diagnoses are discussed.