Embryonal tumors with multilayered rosettes (ETMR) are rare, highly aggressive brain neoplasms predominantly affecting children under 3 years of age. In the 2021 WHO Classification of Tumors of the Central Nervous System, ETMRs are classified as grade IV tumors, previously considered separate entities such as embryonal tumor with abundant neuropil and true rosettes (ETANTR), ependymoblastoma (EBL). We report a 13-month-old girl who presented with afebrile seizures, left hemiparesis, and status epilepticus. Neuroimaging revealed a right fronto-parieto-temporal mass with typical features of ETMR, confirmed by stereotactic biopsy. Despite supportive care and preparation for surgery, the patient's condition deteriorated rapidly, and she passed away 15 days after admission. This case highlights the typical presentation, imaging characteristics, and poor prognosis of ETMR, emphasizing the importance of early recognition and molecular testing in enhancing diagnosis and treatment strategies.

Embryonal tumor with multilayered rosettes (ETMR) is a rare and deadly pediatric central nervous system tumor often seen before the age of 3. ETMR consists of embryonal tumors with abundant neuropil and true rosettes, ependymoblastoma, and medulloepithelioma. The 5-year survival rate has been reported to be between 0% and 30%. Treatment of ETMR is very unstandardized and typically consists of surgical resection, chemotherapy, and radiotherapy. A systematic review was performed to better understand treatment-related outcome trends. The authors performed a PRISMA guidelines-based systematic review of the literature. Survival curve analysis using Kaplan-Meier curves and Cox proportional hazards models were used to estimate survival rates between 2 groups and multiple risk factors, respectively. The average survival time was 31.1 months in patients treated with radiotherapy compared to 11.2 months in patients who did not. Radiotherapy was a significant covariate on overall survival (P < .001) with an 82% lower risk of death compared to patients who did not receive radiotherapy. The average survival time for patients with focal radiotherapy was 35.8 months compared to 29.8 months in patients with CSI radiotherapy, but there was a great number of patients with pretreatment metastasis in the CSI group. In patients without pretreatment metastasis, focal radiotherapy had non-inferior outcomes for survival rates and times. Patients treated with radiotherapy in addition to chemotherapy demonstrated a significantly higher survival time. For patients with no metastasis prior to treatment, focal radiotherapy should be strongly considered.

Embryonal tumors with multilayered rosettes (ETMR) are highly aggressive and therapy-resistant pediatric central nervous system (CNS) tumors that have three histological patters: embryonal tumor with abundant neuropil and true rosettes, ependymoblastoma, and medulloepithelioma. We present a case of ETMR in an 18-year-old woman with DICER1 syndrome. This report confirms the important role of DNA-methylation analysis in the classification of CNS embryonal tumors and the importance of investigating somatic and germline DICER1 mutations in all CNS embryonal tumors.

Ependymoblastoma is a rare embryonal neoplasm of the nervous system, and the entity is even rare with distant metastasis. This case can help refine the existing literature and provide lessons for the management of other patients with ependymoblastoma. The present case concerns an adolescent with supratentorial ependymoblastoma, who received gross-total resection (GTR), postoperative radiotherapy, and six cycles of chemotherapy, with disease-free survival (DFS) of about 5.3 years. Subsequently, pulmonary metastasis occurred, but no intracranial lesion was found. Finally, combined treatment with radiotherapy and chemotherapy significantly reduced the lung lesions, with progression-free survival (PFS) of 10 months and long-term survival of 6.3 years. This case indicates that the lung metastases of ependymoblastoma are relatively sensitive to radiation, but lung metastases have not completely disappeared. Perhaps, increasing the radiation dose to lung metastases can improve the efficacy, which is worth exploring.

Extraosseous dural-based primary Ewing's sarcoma of the central nervous system is a rare tumour posing a diagnostic challenge. On cross-sectional radiological imaging, the lesion has an extra-axial location with heterogeneous appearance. These lesions are usually multicystic with internal haemorrhage causing fluid-haematocrit levels. It mimics conditions like an aneurysmal bone cyst, microcystic meningioma, telangiectatic osteosarcoma or cystic metastasis. Exclusion of primary Ewing's sarcoma or malignancy elsewhere in the body is required to rule out a secondary. Surgery along with adjuvant chemotherapy and focal radiotherapy is the preferred mode of treatment. Due to the presence of non-specific small round blue cells on H&E stain, these tumours are also confused with lymphoma, osteosarcoma, rhabdomyosarcoma, Merkel cell carcinoma, ependymoblastoma and neuroendocrine carcinoma. Immunohistochemistry provides a definitive diagnosis. A high degree of suspicion in the preoperative scans is crucial for prognostication and early management of this aggressive tumour leading to improved patient survival.