Primary Intracranial Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor Mimicking Meningioma: A Case Report and Literature Review

Primary intracranial peripheral primitive neuroectodermal tumor: lessons from an exceptionally rare neoplasm. Illustrative case

BACKGROUND

The primary intracranial peripheral primitive neuroectodermal tumor (pPNET) is a lesion subtype within the Ewing sarcoma family of tumors. pPNETs are extremely uncommon pathologies, accounting for 0.03% of intracranial tumors and 1% to 2% of Ewing sarcoma cases. Given its histological aspect similar to other highly proliferative malignant neuroectodermal neoplasms, pPNET merits extensive workup for accurate diagnosis and treatment.

OBSERVATIONS

A 36-year-old male presented to the emergency department with a 1-year history of headaches in the right frontoparietal area, generalized tonic-clonic seizures, and a history of the resection of a tumor labeled as a meningioma 5 years before admission. He was neurologically intact. Brain magnetic resonance imaging revealed a heterogeneous focal lesion of 25 × 35 × 23 mm with a necrotic center and neoformative appearance in the right frontal cortex. The patient underwent multimodal treatment with gross-total resection, radiotherapy, and chemotherapy. Histopathological examination results supported the diagnosis of pPNET. At the 2-year follow-up, the patient had no new-onset symptoms, and brain imaging revealed absent signs of tumor recurrence.

LESSONS

The present case describes an extraordinary pPNET case, initially confounded as a clear cell meningioma. Managing pPNET requires thorough investigation, careful differentiation from similar neuroectodermal lesions, and multimodal treatment to improve the patient's prognosis.

Primary Intracranial Ewing Sarcoma With an Unusual Presentation: A Case Report

Primary extraosseous intracranial Ewing sarcoma (ES) is an extremely rare disease, limited to the pediatric population, that primarily originates in the skull. Here, we present an unusual case of adult Ewing's sarcoma originating from the brain parenchyma. The 50-year-old male patient visited our hospital with severe headache lasting 3 weeks. MRI presented 6.1×6.2×5.2 cm sized heterogeneously enhanced mass containing peritumoral edema in the right frontal lobe. The patient underwent right frontal craniotomy, at which time the gray and red masses adhered to the surrounding brain parenchyma. The mass was completely resected using neuronavigation and electrophysiological monitoring. Histopathological examination revealed ES-compatible findings of small round cell tumor and CD-99 positive membranous immunostaining. Next generation sequencing revealed translocation and fusion of EWSR1 and FLI1, consistent with a confirmed diagnosis of ES. Consequently, the patient underwent postoperative radiotherapy. The present case revealed adult primary intracranial ES arising from the frontal lobe. Although its etiology remains poorly understood, intraparenchymal ES should be included in the differential diagnosis of parenchymal brain tumors.

Primary Intracranial Ewing Sarcoma With EWSR1-FLI1 Gene Translocation Mimicking a Meningioma and a Multidisciplinary Therapeutic Approach: A Case Report and Systematic Review of Literatures

Ewing sarcoma and peripheral primitive neuroectodermal tumor (ES/pPNET) is an undifferentiated malignant tumor that is most prevalent in children and young adults and often radiologically mimics a meningioma. A 38-year-old female patient visited our hospital with complaints of right-sided tinnitus, right hemiparesis, and imbalance. She underwent preoperative imaging and was subsequently diagnosed as having a meningioma on the petrous ridge. After partial resection, EWSR1-FLI1 gene fusion was confirmed, and she was diagnosed with ES/pPNET. The tumor was successfully treated using a multidisciplinary approach of adjuvant chemo- and radiotherapy. This case is noteworthy because it is an extremely rare case of an intracranial ES/pPNET, and it is worth sharing our clinical experience that the tumor was successfully treated through a multidisciplinary therapeutic approach even though complete resection was not achieved.

Primary Intracranial Ewing Sarcoma Invading the Superior Sagittal Sinus with EWSR1-FLI1 Gene Fusion and EWSR1 Gene Mutation: A Case Report and Literature Review

BACKGROUND

Primary intracranial Ewing sarcoma (ES) is an extremely rare intracranial malignant tumor, mostly occurring in children and adolescents. Because of its rarity, the magnetic resonance imaging (MRI) features and treatment strategies of primary intracranial ES are still unclear.

METHODS

The purpose of this study was therefore to report a case of primary intracranial ES, whose molecular features included both EWSR1-FLI1 (EWS RNA binding protein 1- Friend leukemia integration 1) gene fusion and EWSR1 gene mutation. It is worth noting that this is the first reported case of ES invading the superior sagittal sinus and mostly causing occlusion. At the same time, there were polymorphisms of four drug metabolism-related enzymes in the tumor. Subsequently, we conducted a literature review to characterize the clinical features, imaging findings, pathological features, treatments, and prognoses of primary intracranial ESs.

RESULTS

A 21-year-old female was admitted to the hospital with headache with nausea and vomiting for 2 weeks. An MRI showed a 3.8 × 4.0 cm large heterogeneous mass in the bilateral parietal lobe with peritumoral edema. The tumor invaded the superior sagittal sinus and mostly caused occlusion of the middle segment of the superior sagittal sinus. The mass was successfully removed using a neuromicroscope. Postoperative pathology indicated a primary intracranial ES. High throughput sequencing (next generation sequencing) showed that there was EWSR1-FLI1 gene fusion and EWSR1 gene mutation in the tumor, with polymorphisms of four drug metabolism-related enzymes and low tumor mutational burden. Subsequently, the patient received intensity modulated radiation therapy. The patient has signed an informed consent form.

CONCLUSIONS

The diagnosis of primary intracranial ES depended on histopathology, immunohistochemistry staining, and genetic testing. At present, total tumor resection combined with radiotherapy and chemotherapy is the most effective treatment. We report the first case of primary intracranial ES invading the superior sagittal sinus and causing middle segment occlusion, accompanied by EWSR1-FLI1 gene fusion and EWSR1 gene mutation.

Exploration of Flavonoids as Lead Compounds against Ewing Sarcoma through Molecular Docking, Pharmacogenomics Analysis, and Molecular Dynamics Simulations

Ewing sarcoma (ES) is a highly malignant carcinoma prevalent in children and most frequent in the second decade of life. It mostly occurs due to t(11;22) (q24;q12) translocation. This translocation encodes the oncogenic fusion protein EWS/FLI (Friend leukemia integration 1 transcription factor), which acts as an aberrant transcription factor to deregulate target genes essential for cancer. Traditionally, flavonoids from plants have been investigated against viral and cancerous diseases and have shown some promising results to combat these disorders. In the current study, representative flavonoid compounds from various subclasses are selected and used to disrupt the RNA-binding motif of EWS, which is required for EWS/FLI fusion. By blocking the RNA-binding motif of EWS, it might be possible to combat ES. Therefore, molecular docking experiments validated the binding interaction patterns and structural behaviors of screened flavonoid compounds within the active region of the Ewing sarcoma protein (EWS). Furthermore, pharmacogenomics analysis was used to investigate potential drug interactions with Ewing sarcoma-associated genes. Finally, molecular dynamics simulations were used to investigate the stability of the best selected docked complexes. Taken together, daidzein, kaempferol, and genistein exhibited a result comparable to ifosfamide in the proposed in silico study and can be further analyzed as possible candidate compounds in biological in vitro studies against ES.

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'S SARCOMA IN PEDIATRIC PATIENT RARE CASE: A CASE REPORT

This study reports a 12-year-old male was referred to our institute with a mass in the right ear. The mass was rapidly growing thus needing an immediate surgical attention. MRI revealed an exophytic, hyper vascular mass extending to the right jugular fossa and, the middle ear, and to the right acoustic meatus, suggestive of a right glomus jugulare tumor. Angiography showed a hypervascular lesion with robust feeding from the superficial temporal artery and right occipital artery. After surgery, the patient rapidly recover and he was discharged home on the 5th day after surgery. Three months after surgery, the lump reappeared and grew rapidly as before.

Primary intracranial extraosseous Ewing's sarcoma of the skull base in an elderly adult: illustrative case

BACKGROUND

Primary extraosseous intracranial Ewing's sarcoma, also known as a peripheral primitive neuroectodermal tumor or "small round blue cell tumor," is an extremely rare entity with limited representation in the literature beyond the pediatric population.

OBSERVATIONS

A 67-year-old male suffering occipital headache, nausea, and gait disturbance was found to have a large, avidly contrast-enhancing cerebellopontine angle mass extending into the cervical spinal canal with associated mass effect on medulla, cerebellum, fourth ventricle, and cervical spinal cord. This mass was not present on the imaging from 8 years prior. He underwent surgical debulking and pathology results demonstrated a malignant small round cell tumor showing diffuse immunopositivity for cytokeratins, CD99 and NKX2.2 with EWRS1-FLI1 rearrangement in 84% of the nuclei confirmatory of Ewing's sarcoma. After 14 cycles of chemotherapy and 6 weeks of radiotherapy, 22 months after discovery, the patient remains in clinical and radiographic remission with complete return to his baseline functioning.

LESSONS

Primary skull base extraosseous Ewing's sarcoma should be considered in the differential diagnosis even in the elderly population when imaging studies demonstrate aggressive tumor growth patterns. Tumor debulking to establish a diagnosis followed by adjuvant chemoradiation therapy can result in clinical improvement with remission.

Case report: Primary intracranial EWs/PNET in adults: Clinical experience and literature review

Introduction

Adult primary intracranial Ewing sarcomas (EWs)/primitive neuroectodermal tumors (PNETs) are extremely rare, with only 30 patients published before us. The imaging features and treatment strategies of primary intracranial EWs/PNETs are unclear due to its rarity. The aim of this study was to investigate the clinical features, imaging findings, treatment, survival analysis, and prognosis of adult EWs/PNETs, and a systematic review was conducted based on the patient we treated and published literature.

Case description

A 19-year-old male patient suffered from head pain due to an accidental fall on a motorcycle that occurred more than 10 days before going to the hospital, and underwent computed tomography (CT) examination; it was found that the left temporo-occipital fossa was occupied. Magnetic resonance imaging (MRI) was recommended to understand the nature of the lesion, and the result showed that it has a high probability of being a meningioma. He underwent surgical removal of the mass under general anesthesia, and surprisingly, postoperative pathology revealed EWs/PNET. The disease has a high degree of malignancy, and the patient developed multiple metastases throughout the body 5 years after surgery.

Conclusion

Primary intracranial EWs/PNETs in adult patients are rare, of which imaging findings should be considered as one of the differential diagnoses of meningioma, hemangiopericytoma, and malignant triton tumor. Larger solid-cystic masses with septum-like enhancement may be relatively specific imaging findings of intracranial EWs/PNETs. The prognosis of primary adult intracranial EWs/PNETs is poor. Radical tumor resection combined with radiotherapy and chemotherapy is currently the main and possibly the most effective treatment method.

A rare radiotherapy-sensitive primitive neuroectodermal tumor with APC gene amplification in an adult: a case report and literature review

Primitive neuroectodermal tumor (PNET) of the lung is rare in adults, and treatment options vary. We herein describe the disease course and follow-up of PNET in an adult. A 27-year-old man was admitted to our hospital because of cough and headache, and whole-exome sequencing revealed positive expression of the EWSR1-FLI1 fusion gene and amplification of the APC gene. Although the patient received multidisciplinary treatment including chemotherapy regimens of etoposide plus cisplatin; focal radiotherapy focusing on the cerebrum, lung, and kidneys; and a subsequent palliative gastrointestinal operation, he eventually died of multiple organ functional failure. His overall survival period was 18 months, and his progression-free survival period was 4 months. During the treatment, the patient showed remarkable sensitivity to radiotherapy. In conclusion, PNET of the lung in adult patients is extremely rare, and the prognosis is very poor. Involvement of a multidisciplinary team in the development of personalized therapeutic strategies is essential. This patient with APC gene amplification showed excellent sensitivity to radiotherapy for intrapulmonary and intracranial lesions, suggesting that APC gene amplification may be related to radiotherapy sensitivity. However, further clinical research is needed.

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.

Primary intracranial peripheral primitive neuroectodermal tumor in an adult patient with aphasia: A rare case report

Primary intracranial peripheral primitive neuroectodermal tumors (pPNETs) are extremely rare malignancies that commonly affect children and adolescents. Only 10 cases over the age of 33 have been reported. pPNETs have an aggressive behavior and a high tendency for local recurrence and distant metastasis. Here, we present a case of supratentorial pPNET that affected the left frontoparietal lobe of a 36-year-old female patient. The patient complained of aphasia during the last 2 months. Aphasia is reported for the first time as a result of a pPNET. In T1-weighted MRI, a large mass with mixed isointense to hypointense signals was observed. The tumor was completely removed. Histopathologic examination was indicative of a small round cell tumor. Immunohistochemical analysis showed positivity for CD99. Presence of EWSR1 gene rearrangement confirmed the diagnosis. The patient's aphasia was gradually resolved post-surgery. Six months follow-up showed no evidence of local recurrence or metastasis.