Orbital inflammatory pseudotumors, also known as idiopathic orbital inflammatory syndrome (IOIS) or nonspecific orbital inflammatory syndrome (NSOIS), refer to a group of rare and non-neoplastic conditions characterized by localized inflammation in the orbit. This term encompasses a spectrum of disorders such as orbital myositis, idiopathic sclerosing inflammation, inflammatory orbital masses, and dacryoadenitis, which share similar clinical features.
Orbit inflammatory pseudotumors typically present as painless, indolent, and slowly growing orbital masses. These lesions predominantly affect the soft tissues surrounding the eye, including the extraocular muscles, lacrimal gland, and orbital fat. The exact etiology of these tumors remains unknown, and the diagnosis is primarily based on a combination of clinical findings and imaging studies, such as computed tomography (CT) and magnetic resonance imaging (MRI).
Histopathological examination of the affected tissues reveals a chronic inflammatory infiltrate consisting mainly of lymphocytes, plasma cells, and histiocytes. The absence of granulomas or malignant cells helps differentiate orbicular inflammatory pseudotumors from other orbital neoplasms. Treatment of this condition involves a multidisciplinary approach, including anti-inflammatory medications like corticosteroids to alleviate symptoms and reduce inflammation.
Despite its benign nature, orbit inflammatory pseudotumors may cause significant ocular morbidity if left untreated, leading to proptosis, diplopia, compressive optic neuropathy, and visual loss. Therefore, it is crucial to promptly identify, diagnose, and manage these conditions to achieve optimal outcomes and prevent long-term complications.
