METHODS: A retrospective analysis of 455 cases of orbital soft tissue tumors in our hospital from 2003-11/2018-11 were performed to observe the clinical features, pathological classification and pathological features of rare tumors.

RESULTS:All 455 patients with orbital soft tissue tumors, 421(92.5%)were benign tumors. The top 5 were 258 cases of cavernous hemangioma, 58 cases of capillary hemangioma, 16 cases of neurofibroma, 15 cases of fibroid, and 14 cases of schwannoma; 27 cases(5.9%)of intermediate type, including 23 cases of solitary fibrous tumor(SFT), 2 cases of low-grade malignant fibrous histiocytoma, 2 cases of low-grade mucinous neurofibroma; 7 cases(1.5%)of malignant type, 2 cases of orbital malignant SFT, 2 cases of orbital myeloid sarcoma(MS), mucinous liposarcoma(MLS), spindle cell undifferentiated sarcoma and peripheral primitive neuroectodermal tumor(PNET)1 case. Immunohistochemistry and molecular detection of some cases revealed that the application of new antibodies such as STAT6 and molecular detection techniques can improve the diagnostic accuracy.

CONCLUSION:Benign tumors account for the majority of orbital soft tissue tumors. Cavernous hemangioma in vascular tumors is the first, and there are few soft tissue tumor pathological types such as Erdheim-Chester disease(ECD)and granulomatous ossifying fibers. Tumors(POF), leiomyomas and myxomas; intermediate and malignant tumors are rare; pathological types such as SFT, MLS, spindle cell undifferentiated sarcoma and MS are often difficult to diagnose, easy to miss diagnosis and misdiagnosis, new immunity histochemical antibodies and molecular detection techniques can improve the accuracy of the diagnosis.