AN ORBITAL MASS PRESENTING AS PRIMARY MONOPHASIC SYNOVIAL SARCOMA

Introduction: Primary orbital monophasic synovial sarcoma is an extremely rare tumor with no case report in the literature. Case presentation: A 37-year-old man presented with a twelve-year history of a progressively enlarging, painless mass in the left orbit which had resulted in lateral displacement of the eyeball. Examination showed the presence of a 6x4x3cm tumor on the medial side, associated with limited adduction of the left eye. A complete excision was performed and the eye was preserved. The patient is stable after surgery. Following the definitive histological report a thorough clinical and radiological search has been made for a primary lesion elsewhere in the head and neck, trunk, and limbs with negative results. Conclusion: The diagnosis of monophasic primary orbital synovial sarcoma requires clinical, imaging and immunohistochemical investigation to exclude alternative primary sources. The treatment of choice is excision, which in most of cases is helpful for diagnosis. The prognosis is usually poor