RESUMEN
The cavernous sinus contains significant structures such as the internal carotid artery and cranial nerves III to VI. Cavernous sinus lesions may cause ophthalmoplegia, proptosis, and diplopia. We report a 56-year-old woman who presented with throbbing headache and associated right-sided ocular pain. While awaiting imaging studies, she suddenly developed opthalmoplegia and ptosis of the right eye. She had ipsilateral palsy of the third and fourth cranial nerves, while the sixth nerve remained intact. Magnetic resonance imaging revealed a pituitary gland mass extending into the right cavernous sinus with associated sphenoid sinusitis. The patient underwent endoscopic sinus surgery and subsequent pituitary tumor removal by transsphenoidal approach. During preoperative evaluation, a mass was found protruding in her left bronchus. The pituitary tumor pathologic examination revealed metastatic adenocarcinoma of the lung. In this patient, the initial symptoms of lung cancer were headache and cavernous sinus syndrome, which had metastasized to the pituitary gland.