Abstract: Objective To investigate the clinicopathological features, diagnosis, differential diagnosis and prognosis of adult orbital xanthogranulomatous disease. Methods The clinical and pathology data of one 56 year old male patient with Adult orbital xanthogranulomatous disease(AOXGD)were retrospectively analyzed, along with a review and summarize of the relevant literatures. Results The patient was male, 56 year old. Both eyelid masses were found for 7 years, with gradual enlargement. Giant examination: a upper eyelid mass of the left eye, size 1.0 cm×0.8 cm×0.3 cm, section surface gryxanthin tough, left eye eyelid mass, size 3.0 cm×2.0 cm×0.9 cm section gryxanthin. Microscopy: The lesion is located in the subcutaneous tissue with multiple histiocytic infiltration, Partly acidophilic and biased, the majority of histiocytes were foamy, Background with unequal amounts of lymphocytes, plasma cells, multinucleated giant cells(Duton cells), and foamy id histiocytic infiltration in local skeletal muscle. Immunophenotype: histiocytes were positive for CD68 and CD163, TREM-1 negative for CD1a, S-100 and Lahrin-, about 5% Ki67. BRAF V600E gene detection without mutation. Conclusion AOXGD is relatively rare in clinical practice, with multiple pathological subtypes, making diagnosis and treatment difficult and prone to misdiagnosis and mistreatment. Among them, AOX subtype with simple surgical resection has a good prognosis, while ECD subtype has the worst prognosis. Patients with BRAF V600E mutation can be treated with targeted drug Verofinib. TREM-1 may participate in the formation of foam like tissue cells and be related to the occurrence of AOXGD. It is expected to become a new target for AOXGD treatment or a new indicator for monitoring the recurrence and progress of AOXGD.

Key words: Adult orbital xanthogranulomatous disease, Subtype, Immunohistochemistry, Differential diagnosis, TREM-1