Orbital Chordoma Presenting as Unilateral Proptosis: A Rare Extraskeletal Presentation

Introduction: Chordomas are rare malignant tumors of notochordal origin, confined to the axial skeleton. Primary extraskeletal orbital chordoma is exceptionally rare and often radiologically indistinguishable from more common orbital neoplasms, leading to diagnostic uncertainty and delayed management. Case Presentation: A 59-year-old male presented with progressive right-sided proptosis, visual decline, and ocular discomfort over six months. Clinical examination revealed non-pulsatile proptosis with restricted extraocular movements and exposure keratopathy. Imaging demonstrated a heterogeneously enhancing orbital mass without bony involvement, initially suggestive of a primary orbital neoplasm. The patient underwent orbital exenteration. Histopathological examination revealed physaliphorous cells in a myxoid stroma, and immunohistochemistry showed positivity for cytokeratin, epithelial membrane antigen, S-100, and brachyury, confirming orbital chordoma. Postoperative recovery was uneventful.Conclusion: Orbital chordoma is a rare entity that may present without radiological evidence of bony involvement. Inclusion of chordoma in the differential diagnosis of orbital masses and timely histopathological evaluation are crucial for accurate diagnosis and optimal treatment planning. Complete surgical resection with adjuvant radiotherapy constitutes the mainstay of treatment, while long-term clinical and radiological follow-up remain imperative because of its locally aggressive nature and high risk of recurrence.