Rare Case of Sellar and Suprasellar Metastasis from Ewing's Sarcoma of Tibia.

We hereby report a case of metastatic Ewing's sarcoma presenting with rapid-onset total ophthalmoplegia, optic atrophy, and right temporal hemianopia. Comprehensive ophthalmic and neurological evaluation with targeted radioimaging revealed a tumor mass centered over the sella, compressing optic chiasma, extending to involve the left cavernous sinus and the left orbital apex. Whole-body imaging revealed the evidence of multifocal lung and mediastinal metastasis with focal lytic defect in the left femoral head. Histopathological evaluation of transnasal punch biopsy from the nasopharyngeal extension of the tumor revealed small round-cell tumor with strong CD99 positivity, supporting the diagnosis of Ewing's sarcoma. Rapid, aggressive extensions of the metastatic tumor into vital structures despite the initiation of chemoradiation of the extensive intracranial tumor led to unexpected demise of the patient. Our case is an unusual case of Ewing's sarcoma metastasis manifesting as a sellar mass and mimicking a pituitary adenoma radiologically, with a rapid progression within 2 weeks to cause massive extension of tumor into suprasellar, infrasellar, and left parasellar area, indicative of highly malignant nature of the tumor.