embryonal tumour with multilayered rosettes
Pronunciation: em-bree-ON-al TOO-mer with mul-tee-LAY-erd roh-ZET-z
A highly aggressive paediatric central nervous system embryonal tumour defined by amplification of the C19MC microRNA cluster on chromosome 19q13.42 and characterised by multilayered (Flexner–Wintersteiner-like) rosettes.
Full Definition
Embryonal tumour with multilayered rosettes (ETMR) is a recently delineated WHO-classified CNS tumour entity that predominantly affects children under three years of age and carries an extremely poor prognosis. It encompasses tumours previously described as embryonal tumour with abundant neuropil and true rosettes (ETANTR), ependymoblastoma, and medulloepithelioma with C19MC alteration. The defining molecular event is focal amplification of the C19MC locus, detectable by FISH or DNA methylation profiling. Editors must render the abbreviation ETMR correctly and should note that its predecessor terms (ETANTR, ependymoblastoma) are now obsolete per the 2021 WHO CNS5 classification.
Usage
Usage note: Predecessor terms (ETANTR, ependymoblastoma) are obsolete under WHO CNS5. Flag their use and recommend replacement with ETMR.
In Context
- "C19MC amplification confirmed the diagnosis of embryonal tumour with multilayered rosettes in the 18-month-old patient." — Neuropathology molecular report
- "Authors using the term 'ependymoblastoma' for a C19MC-amplified tumour should be directed to update the terminology to ETMR per WHO CNS5." — Manuscript editing note