[Retrobulbar optic neuropathy secondary to an undifferentiated carcinoma of the sphenoid sinus].

Undifferentiated carcinoma of the paranasal sinuses is a rare malignant tumor, characterized by rapid growth, local/regional invasion, metastatic potential and poor prognosis despite aggressive treatment. Clinically, this tumor may manifest as episodes of epistaxis, headache or ophthalmic signs, particularly oculomotor nerve palsies, optic atrophy or even proptosis in the case of orbital extension. We report the case of a patient admitted with a left retrobulbar optic neuropathy, which led to a diagnosis of undifferentiated carcinoma of the sphenoid sinus.