An unusual biconvex epidural lesion: acutely presenting extraosseous intracranial Ewing's sarcoma

Intracranial peripheral primitive neuroectodermal tumor presenting as neurosurgical emergency: A report of two cases

Ewing's sarcoma/peripheral primitive neuroectodermal tumor (ES/pPNET) belongs to the family of malignant small and blue round cell tumors. It usually occurs in children and young adults with 3/4th of the cases arising from bone and 1/4 from soft tissue. Here, we present two cases of intracranial ES/pPNET who presented with mass effect. Management consists of surgical excision followed by adjuvant chemotherapy. Intracranial ES/pPNETs are highly aggressive and rare malignancies, reported to comprise of 0.03% of all intracranial tumors. The most common genetic aberration associated with ES/pPNET is chromosomal translocation t (11,12) (q24;q12). Patients with intracranial ES/pPNETs may present in acute or delayed manner. The presenting symptoms and signs depend on the location of the tumor. Intracranial pPNET although slow growing, they are highly vascular and may present as neurosurgical emergencies due to mass effect. We have presented the acute presentation of this tumor and its management.

Extraskeletal Ewing Sarcoma from Head to Toe: Multimodality Imaging Review

Extraskeletal Ewing sarcoma (EES) is a rare subtype in the Ewing sarcoma family of tumors (ESFT), which also includes Ewing sarcoma of bone (ESB) and, more recently, primitive neuroectodermal tumors. Although these tumors often have different manifestations, they are grouped on the basis of common genetic translocation and diagnosis from specific molecular and immunohistochemical features. While the large majority of ESFT cases occur in children and in bones, approximately 25% originate outside the skeleton as EES. Importantly, in the adult population these extraskeletal tumors are more common than ESB. Imaging findings of EES tumors are generally nonspecific, with some variation based on location and the tissues involved. A large tumor with central necrosis that does not cross the midline is typical. Despite often nonspecific findings, imaging plays an important role in the evaluation and management of ESFT, with MRI frequently the preferred imaging modality for primary tumor assessment and local staging. Chest CT and fluorine 18 fluorodeoxyglucose PET/CT are most sensitive for detecting lung and other distant or nodal metastases. Management often involves chemotherapy with local surgical excision, when possible. A multidisciplinary treatment approach should be used given the propensity for large tumor size and local invasion, which can make resection difficult. Despite limited data, outcomes are similar to those of other ESFT cases, with 5-year survival exceeding 80%. However, with metastatic disease, the long-term prognosis is poor. ^©RSNA, 2022.