Abstract:AIM: To explore the clinical and pathological characteristics of thirteen patients with orbital liposarcoma. METHODS: The clinical history data of thirteen patients diagnosed as orbital liposarcoma at Beijing Tongren Hospital, from 2006 to 2021 were collected and analyzed. The data includes age, gender, affected orbital side, course of disease, status of disease (primary or recurrent), clinical manifestations, preoperative visual acuity, operative treatment, the relations between liposarcoma and surrounding tissue, longest diameter of liposarcoma, histological subtype, immunohistochemical indicators, follow-up treatment and prognosis. RESULTS: The initial symptoms are diverse. Proptosis is the most frequent chief complaint and the others included vision loss, epiphora, diplopia, and eyelid palpable mass. Results of imaging examination [computed tomography (CT) or magnetic resonance imaging (MRI)] showed orbital mass. In terms of treatment, 10 patients received tumor resection, and the mean longest diameter of the tumor was 3.39±1.36 cm. The other 3 patients had optic nerve invaded, so they received orbital exenteration. Pathological examination results confirmed the diagnose of liposarcoma for 13 patients. Six patients displayed as myxoid type, and three patients in each type of dedifferentiated and well-differentiated type. One patient was verified as pleomorphic, which was a rare type of liposarcoma. All of the patients showed Vimentin positive, and most showed CD34 and S-100 positive. Besides, four patients showed smooth muscle actin positive. All thirteen patients were alive. CONCLUSION: Orbital liposarcoma is a rare disease and it has no specific clinical manifestation. The diagnosis of liposarcoma should be considered when proptosis and orbital mass occurred in orbit. It is recommended to perform pathological examination to achieve early detection and early treatment.