Tangtammaruk P.Uiprasertkul M.Lumyongsatien M.Mahidol University2023-05-192023-05-192023-01-01International Medical Case Reports Journal Vol.16 (2023) , 215-219https://repository.li.mahidol.ac.th/handle/20.500.14594/82515Extraocular muscle lipoma is a rare benign mesenchymal tumor of the orbit. We report a case of a 37-year-old woman who presented with chronic progressive proptosis and inferior globe displacement of left eye. External eye examination revealed a yellowish mass at the superior bulbar conjunctiva. Magnetic resonance imaging showed a well-circumscribed mass confined in the superior rectus muscle belly and tendon with a fat signal. Debulking surgery was performed using the transconjunctival and vertical lid split approach. A pathological study demonstrated matured adipose tissue cells encapsulated by a thin layer of fibrous tissue, in addition to the chronic non-specific inflammation of the tenon capsule tissue sample. Histopathological findings of the mass were consistent with a well-circumscribed intramuscular lipoma. The symptoms of the patient were significantly improved 3 months after surgical and short-course systemic steroid treatments. However, long-term surveillance is needed.MedicineArticleSCOPUS10.2147/IMCRJ.S3963822-s2.0-851524224021179142X