Inflammatory Pseudotumor: Idiopathic orbital inflammation is the preferred name for this space occupying inflammatory disorder of the orbit that simulates a neoplasm. Patients usually report abrupt onset of diffuse or compartmentalized orbital pain and various other symptoms. Clinical signs can include diplopia, restricted EOM, lid erythema, edema and vascular congestion. This is a diagnosis of exclusion, so other causes of orbital inflammation must be ruled-out. Patients may have an increased SED rate, positive ANA and pleocytosis of CSF. Scans (1) often show nonspecific inflammation of the soft tissues of the orbit, and biopsy reveals a nongranulomatous cellular infiltrate, often with fibrosis of tissue. Note the eosinophils which are often present among the acute inflammatory cells. Most patients respond to systemic steroids. If not , chemotherapeutic agents or orbital radiation may be of benefit. Back to Orbit