Orbital Epstein–Barr virus associated smooth muscle tumor in an immunocompromised patient with T-cell deficiency

Epstein-Barr Virus-associated smooth muscle tumors (EBV-SMTs) are rare neoplasms that primarily occur in immunocompromised individuals. Orbital EBV-SMTs are an exceptionally rare subset of these tumors which may cause mass effect that leads to functional impairment. We report a case of a patient with systemic lupus erythematosus on long-term corticosteroids who was later found to have T cell deficiency and markedly reduced CD4 and CD8 counts. She presented with a rapidly enlarging right orbital mass causing proptosis, optic nerve compression, and visual dysfunction. Imaging revealed an extraconal lesion with bony erosion and sinus extension. Histopathology confirmed the diagnosis of EBV-SMT. The patient was managed by a multidisciplinary team including Ophthalmology (Oculoplastic Surgery) and Otorhinolaryngology (Rhinology). Pre-operative 3D-printed models were used for surgical planning. Tumor debulking was then performed using a combined transorbital and endoscopic endonasal approach, together with intraoperative CT and MRI-based image guidance to maximize safety and preserve optic nerve function. Systemic screening identified additional EBV-SMT lesions requiring surgical intervention, and sirolimus therapy was initiated as a possible immunomodulatory adjunct to slow the growth of these multifocal tumors. There is currently no standardized treatment for orbital EBV-SMTs. Surgical resection or debulking remains the mainstay, but complete excision may be limited by anatomical constraints. Immune reconstitution, together with targeted therapies such as sirolimus and bevacizumab offer additional options. This case highlights the importance of considering EBV-SMT in immunocompromised patients with rapidly enlarging orbital masses. Multidisciplinary management, including surgery, systemic evaluation, and immune modulation, is crucial to optimize outcomes.