Dural metastasis of Ewing’s sarcoma
A 24-year-old right-handed female was admitted to our hospital complaining of a 2-week history of moderate headache and weakness in her left leg for the past 2 days. She did not present with nausea, vomiting, dizziness, or seizures but reported an underestimated weight loss in the last 3 months.\nHer medical history was significant for a Pelvis Ewing’s sarcoma, operated with complete surgical removal and stabilization one and a half year ago [], and was recently diagnosed as having small lung metastases.\nOn admission, the patient’s neurological examination revealed no cognitive deficits but a left sided leg monoparesis with motor strength of 3/5. The deep tendon reflexes in her left leg were hyperreactive and the gait and standing position were impossible. Fundoscopic examination showed a grade II papilledema. The physical examination disclosed neither local signs of relapse at the primary site nor other clinical signs of metastatic spread.\nThe computed tomography (CT) scan showed an extra-axial, dural based, heterogeneously hyperdense, and enhancing lesion in the right frontoparietal parasagittal region, with moderate circumferential edema and mass effect []. No abnormalities in the skull abutting to the tumor were noted [] and imaging features were strongly suggestive of a meningioma.\nMagnetic resonance imaging (MRI) delineated better the tumor with its marked surrounding edema. The tumor appeared hypointense on T1-weighted MRI scans, hyperintense on T2-weighted MRI scans and displayed important enhancement with gadolinium. The tumor was attached to the dura of the convexity with present dural tail sign and invaded partially the superior sagittal sinus increasing evidence of a meningeal tumor [].\nThe patient underwent a right frontoparietal craniotomy with an amazing discovery: The tumor was associated with a small lobulated epidural extension tightly attached to the skull []. Macroscopic examination showed a reddish gray, rubbery in consistency and vascular tumor of dural origin. The tumor invaded the superior sagittal sinus but has clear delineation with cerebral parenchyma allowing near total excision; only a small portion involving the superior sagittal sinus was left and the remaining dural edges were coagulated.\nThe definitive histological diagnosis was metastatic Ewing’s sarcoma. The tumor was composed of densely packed, small round, dark staining cells with scanty cytoplasm on light microscopy []. A strong MIC-2 antigen expression was noted on immunohistochemical study.\nThe patient’s immediate postoperative course was uneventful, and she recovered quickly. Her neurological condition improved continuously, and follow-up examinations showed that the monoparesis had disappeared completely. A postoperative CT scan confirmed the extent of tumor resection with a postoperative craniotomy defect [].\nThe patient was administered a 55 Gy radiation therapy along with an adjunctive high dose chemotherapy associating alkylating agents and doxorubicin. Clinical status remained unchanged till the most recent follow-up examination, 8 months after surgery.