Mechanical Thrombectomy for Cerebral Venous Sinus Occlusion Due to Ewing Sarcoma: A Case Report.

Objective: To assess the efficacy of mechanical thrombectomy (MT) for cerebral venous sinus thrombosis associated with Ewing sarcoma invasion into the venous sinus. Case Presentation: A 48-year-old woman presented to our hospital with left hemifacial paralysis. The patient had undergone surgical treatment for left subclavian Ewing sarcoma 24 years ago. Furthermore, the patient had undergone tumor resection for very late metastasis in the left occipital bone and mastoid air cells 3 years prior to her admission. As the Ewing sarcoma had extended to the left transverse sinus, the sinus was resected during craniotomy. The tumor remained in the mastoid air cells, and radiotherapy was administered. On admission to our hospital, FLAIR revealed hyper-intensities in the straight sinus and the superior sagittal sinus. Magnetic resonance venography revealed no signal in the posterior part of the superior sagittal sinus and the bilateral transverse sinuses. The patient was diagnosed with cerebral venous sinus thrombosis, and anticoagulation therapy was administered. However, the swelling and pain on the left side of the face worsened, and intraocular pressure (IOP) increased. Therefore, an MT was performed. After endovascular treatment, the patient's facial swelling and pain were reduced, and IOP returned to normal. Pathological examination of the captured thrombus revealed tumor cells, suggesting venous sinus invasion of Ewing sarcoma. Conclusion: Although it was a palliative treatment, MT was effective in confirming the diagnosis of tumor invasion into the venous sinus and improving the patient's quality of life.