Idiopathic granulomatous orbital inflammation is a chronic inflammatory condition of orbital tissues related to orbital pseudotumor (Mombaerts et al).


Clinical findings:

(1) unilateral orbital mass

(2) clinical signs of inflammation may be present

(3) biopsy shows chronic inflammation with fibrosis and noncaseating granulomas

(4) response to surgery and systemic corticosteroids

(5) absence of extra-orbital granulomatous inflammation and/or vasculitis

(6) negative cultures


Differential diagnosis includes:

(1) sarcoidosis (extra-orbital skin lesions, hilar lymphadenopathy)

(2) tuberculosis or atypical mycobacterial infection (positive culture or stain; lung involvement)

(3) deep fungal infection (positive culture or stain; lung involvement)

(4) foreign body reaction (polarizable material; history of trauma or surgery; rupture of cyst)

(5) Wegener's granulomatosis (c-ANCA positive, necrotizing vasculitis, lung involvement)

(6) rheumatoid nodule (rheumatoid arthritis, fibrinoid material)

(7) microfilaria or other tissue migrating parasite (travel history, positive serology, demonstration of organism)


Sarcoidosis should not be diagnosed solely by an increase in angiotensin-converting enzyme (ACE), since this is increased in any granulomatous disorder.


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