Ewing sarcoma (EWS)/primitive neuroectodermal Tumor (PNET) is a highly malignant small round cell tumor that predominantly affects bone and soft tissue. Ewing sarcoma (EWS) is currently considered the second most common pediatric primary bone malignancy, with osteosarcoma being the most common1–6. It originates mainly from the long bones or the axial skeleton, including the pelvis, ribs, and vertebrae. It is defined as an undifferentiated, malignant, small round cell tumor that prefers bone and soft tissues. James Ewing first described it as "diffuse bone endothelioma" in 1921. Primary intracranial EWS has been demonstrated extremely rarely. It is considered a distinct subtype of extraosseous EWS, based on the fact that its most common origin is the dura mater and is estimated to constitute 1–4%7–8.
Ewing sarcoma breakpoint region 1 (EWSR1) and several common gene fusions are well known. In this tumor. Approximately 85–90% of EWS/PNETs contain a t(11;22) chromosomal translocation, 10–15% have a t(11;22) chromosomal translocation. Considering the fact that it is primary intracranial, EWS is an entity that is not very well and comprehensively defined in the literature clinically and radiographically. In this case, we present a case with its symptoms, histopathological features, and follow-up results.
The 14-year-old girl was seen several times by the general pediatrician for dizziness for 2 months. She. After the patient had complaints of numbness and numbness on the right side for the past 1 week and weakness on the right side, magnetic resonance imaging of the patient showed a mass lesion (Fig. 1). Dural based brain parenchyma is under pressure and causing shift. A case of meningioma with heterogeneous enhancement and thought to be Dural origin was considered the patient was started on anti-epileptic therapy, levetiracetam. No tumor was found in a different part of the body in the preoperative abdominal ultrasonography and computed tomography examinations. The cranial computerized tomography showed that the bone or dura eroding the bone developed hemiparesis on the right side of the patient while he was in the hospital. The patient was taken to an urgent surgery.
Management And Prognosis
With a bi-coronal skin incision, a wide fronto-parieto-occipital craniotomy flap crossed to the opposite side was used. Per-operative image of the mass showed Dural-based and penetrating brain parenchyma, Due to its proximity to the sagittal sinus, preoperative magnetic resonance venography (MRV) imaging was performed on the patient (Fig. 2). MRV showed sagittal sinus was intact and functional. The mass was excised gross totally and the tissues around the intact sagittal sinus were left (Fig. 3). The Dural parts and bone to which the mass was attached were excised and sent to pathological examination. Per-operative histopathological examination result was compatible with malignancy consisting of small blue round cells. Duraplasty and cranioplasty were performed in the same session using synthetic dura graft (Duragen, Integra, USA) and titanium mesh. Postoperative contrast enhanced MRI revealed that the mass was gross totally excised and there was no intracranial hemorrhage (Fig. 4). Preoperative right-sided weakness continued in the postoperative period, and intravenous 3% sodium solution was given for 1 week as anti-edema treatment. After the anti-edema treatment, the patient's neurological deficits improved at the end of the 1st week.
At the end of the 3rd postoperative week, the patient's pathological examination was completed and the EWS was confirmed. Bone marrow biopsy and peripheral blood smear tests were performed on the patient. However, no tumor was detected in any part of his body. The patient was given adjuvant chemotherapy. The patient, who did not have any neurological complaints, came to the 6th month follow-up. Contrast-enhanced cranial magnetic resonance imaging was performed (Fig. 5). No recurrence was detected in MRI, and the patient was included in the follow-up list after receiving the consultations of the pediatric hematology and oncology departments. No additional chemotherapy or radiotherapy was given.