Benign Chondroid Syringoma of the Orbit: A Rare Cause of Exophthalmos

Chondroid syringoma (CS) of the orbit is an extremely rare benign neoplasm. To the best of our knowledge, this is the second case reported in the English literature. We report a case of a 41-year-old woman with orbital CS. This tumor developed slowly over 8 years causing indolor, no axil, exophthalmos of the left eye. Computed tomography demonstrated an isodense intraorbital tumor with homogeneous enhancement without bony erosion. On magnetic resonance imaging the tumor was isointense on T1-weighted imaging, slightly hyperintense on T2-weighted imaging, and enhanced after gadolinium administration. The patient was operated via left lateral orbitotomy. At surgery the mass was well circumscribed, extraconal, very firm and did not invade or adhere to other structures. The tumor was removed in toto. The diagnosis was confirmed by histopathological examination, the lesion was nodular, and there was differentiation toward the adnexal ductal epithelium with chondromyxoid and adipocytic differentiation in the stroma. No recurrence was seen with 1 year follow-up. CS should be included in the differential diagnosis of intraorbital tumors. Complete resection remains the best therapeutic option to prevent recurrence. Close follow-up is recommended because malignant transformation, although rare, is possible.