Adult Orbital Xanthogranulomatous Disease: a retrospective analysis on clinical characteristics, serological examination and immunohistochemical findings of different subtypes

Purpose: Adult orbital xanthogranulomatous disease (AOXGD) is a rare non-Langerhans cell histiocytosis comprising four syndromes, which were only reported in some case reviews. Here we summarized characteristics of 20 AOXGD patients to explore the ethnic features of these disease. Methods: Patients of definite AOXGD diagnosis undergoing treatment were reviewed. Clinical characteristics were collected and analyzed. Results: 20 AOXGD patients were composed of 10 adult-onset asthma and periocular xanthogranuloma (AAPOX), 7 necrobiotic xanthogranuloma (NBX), 3 adult-onset xanthogranuloma (AOX). All cases were bilateral involved with symptoms of nodularity, yellow discoloration, eyelid swelling and mechanical ptosis. 10 patients (45%) had elevated serum IgG4 with average of 2.97±2.29g/L, which was significantly associated with relative eyelid thickness (RET) and orbital involvement (dominant in AAPOX subtype, P<0.05). The ratio of IgG4/IgG positive plasma cells in tissues was from 2.9% to 33.4%. Based on the IgG4 related disease (IgG4-RD) diagnostic criteria, no AOXGD patients met the definitive diagnostic criteria of IgG4-RD. All patients underwent surgeries to remove most lesions and obtain definite pathological diagnosis, then following methylprednisolone and methotrexate administration. After the treatment, ptosis and swelling were significantly corrected without local recurrence. The immunohistochemistry results showed that the TIMP- 1 protein level was higher in AOXGD tissues than in normal tissues. Conclusions: In our cases AOXGD is a rare and special disease characterized by elevated serum IgG4 alone, especially in AAPOX subtype. Degree of eyelid swelling and orbital involvement in AOXGD is significantly associated with serum IgG4 level, which serves as a potent indicator to choose the therapeutic regimen and operation opportunity. Surgery assisted with methylprednisolone and methotrexate administration is an effective therapy for AOXGD. Inflammatory processes participated in the development of AOXGD and thus AOXGD may be a kind of inflammatory disease.