Embryonal tumour with multilayered rosettes
Rare pediatric CNS tumor with poor prognosis and C19MC amplification.
Embryonal tumor with multilayered rosettes (ETMR) is a rare central nervous system embryonal tumor arising from partially differentiated or undifferentiated neuroepithelial cells. It can occur anywhere in the brain, often at multiple sites, and has a high probability of spreading through cerebrospinal fluid. The tumor was not recognized as a distinct entity until molecular analysis distinguished it from other CNS primitive neuroectodermal tumors.
Quick Facts
- Prognosis
- Life expectancy ~ 10 months with treatment (5 year survival <30%)
- Treatment
- Surgery
- chemotherapy
- radiation
- Diagnosis
- CT scan
- MRI scan
- tissue biopsy
- Causes
- C19MC amplification
- Onset
- ~2 years old
- Field
- Neuro-oncology, neurosurgery
Facts from the source article.
Classification
The current WHO Classification of Tumors of the Central Nervous System (5th edition) lists six subtypes of embryonal CNS tumor, including embryonal tumor with multilayered rosettes. Previously, ETMRs were diagnosed as medulloepithelioma, ependymoblastoma, or embryonal tumor with abundant neuropil and true rosettes. Molecular analysis showed these histologic types share common molecular features, leading to their reclassification as a single molecularly defined entity.
Diagnosis
Diagnosis requires biopsy with molecular analysis. The main molecular marker is amplification of the C19MC microRNA cluster, detected by FISH, SNP arrays, DNA methylation arrays, or next-generation sequencing. High expression of LIN28A, identified by immunohistochemistry, is also characteristic and rarely seen in other brain tumors. About 10% of ETMRs lack C19MC amplification but retain LIN28A expression; these tumors often have alterations in other miRNA genes or in miRNA-processing machinery such as DICER1.
Management and prognosis
Complete surgical resection is attempted for localized disease and may improve survival, but carries high risk in young children and is not always feasible due to tumor location. No standardized treatment exists; strategies often include induction chemotherapy followed by high-dose chemotherapy with autologous stem cell rescue. Radiation therapy is sometimes used but may cause cognitive impairment in young children. Prognosis remains poor, with 5-year overall survival below 30% and frequent rapid, treatment-refractory progression.
Frequently Asked Questions
How is Embryonal tumour with multilayered rosettes treated?
Treatment of Embryonal tumour with multilayered rosettes includes surgery, chemotherapy and radiation.
How is Embryonal tumour with multilayered rosettes diagnosed?
Diagnosis of Embryonal tumour with multilayered rosettes is based on CT scan, MRI scan and tissue biopsy.
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