"T1: decreased intensity"
"T2: increased intensity"
"T1 C+ (Gd): patchy or no contrast enhancement"
"Previously embryonal tumours with multilayered rosettes (ETMR) were known as embryonal tumour with abundant neuropil and true rosettes (ETANTR). This term was, however, removed from the 2016 update to WHO classification of CNS tumours in favour of embryonal tumours with multilayered rosettes (ETMR) which incorporates not only ETANTR but also ependymoblastoma and primitive neuroectodermal tumour of the central nervous system (CNS PNET), which have also been removed 6."
"Previously embryonal tumours with multilayered rosettes (ETMR) were known as embryonal tumour with abundant neuropil and true rosettes (ETANTR). This term was, however, removed from the 2016 update to WHO classification of CNS tumours in favour of embryonal tumours with multilayered rosettes (ETMR) which incorporates not only ETANTR but also ependymoblastoma and primitive neuroectodermal tumour of the central nervous system (CNS PNET), which have also been removed 6."
"The terminological changes have resulted from the presence of amplification of the C19MC microRNA cluster on chromosome 19 in both CNS PNET and ETANTR, suggesting that these are the one entity with variable growth pattern 6. Similarly, medulloepithelioma no longer appears as a distinct entity in the 5th Edition (2021) of WHO classification of CNS tumours, and is stated to be "not recommended" terminology 7."
"Typically these tumours are characterised by undifferentiated neuroepithelial cells resembling those of classic CNS PNET (historical), abundant well-differentiated neuropil, and ependymoblastic rosettes scattered throughout paucicellular regions of neoplastic neuropil. It has very characteristic ependymoblastic rosettes in both highly cellular as well as acellular areas."
"If C19MC amplification is absent, then these tumours are known as ETMR-NOS even if other mutations (e.g. DICER1) are identified 6,7."
"AT/RT"
"AT/RT"
"CNS tumour with BCOR internal tandem duplication"
"If C19MC amplification is absent, then these tumours are known as ETMR-NOS even if other mutations (e.g. DICER1) are identified 6,7."
Expected headings
"Staging"
"Previously embryonal tumours with multilayered rosettes (ETMR) were known as embryonal tumour with abundant neuropil and true rosettes (ETANTR). This term was, however, removed from the 2016 update to WHO classification of CNS tumours in favour of embryonal tumours with multilayered rosettes (ETMR) which incorporates not only ETANTR but also ependymoblastoma and primitive neuroectodermal tumour of the central nervous system (CNS PNET), which have also been removed 6."
"Occasionally a distinct histological pattern is encountered that mimics a primitive neural tumour; this is known as a medulloepithelioma pattern."