Perineurioma -a rare cause of proptosis

Perineurioma is a rare benign soft tissue tumor arising from the peripheral nerve sheath. To date only two cases of orbital perineurioma have been reported in literature. A 45-year-old, with no comorbidities, presented with protrusion of the right eye since one-year. Examination revealed 8mm proptosis of the right eye. Dilated fundoscopy of the right eye showed a pale optic disc with choroidal folds temporal to it. Computerised Tomogram (CT) of the orbit showed a well-defined intraconal mass in the inferotemporal part of the orbit. A trans conjunctival orbitotomy with lateral canthotomy was performed and the tumor was removed en bloc. On immunohistochemistry, the tumour was negative for S-100 and showed patchy weak Epithelial Membrane Antigen positivity which was suggestive of a soft tissue perineurioma.