Table of Contents
Embryonal tumor with abundant neuropil and true rosettes, C19MC altered | Ependymoblastoma, C19MC altered | Medulloepithelioma, C19MC not alteredCite this page: Singh N. Embryonal tumor with multilayered rosettes. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/cnstumorETMR.html. Accessed November 27th, 2024.
Embryonal tumor with abundant neuropil and true rosettes, C19MC altered
Definition / general
Essential features
ICD coding
Epidemiology
Sites
Clinical features
Grading
Diagnosis
Radiology description
Case reports
Treatment
Microscopic (histologic) description
Positive stains
Negative stains
Molecular / cytogenetics description
- CNS embryonal tumor with biphasic architecture
- Aggressive CNS embryonal tumor with multilayered rosettes (ETMR), amplicon C19MC altered and C19MC unaltered or not tested (Acta Neuropathol 2016;131:803)
Essential features
- Belongs to ETMR, a new subclassification of embryonal tumors
- Embryonal tumor with abundant neuropil and true rosettes (ETANTR), ependymoblastoma and medulloepithelioma share molecular similarity and comprise a single clinicopathological entity
- Overexpression of LIN28A protein in C19MC altered embryonal tumors
- Poor prognosis
ICD coding
- ICD-10: C71.9 - malignant neoplasm of brain, unspecified
Epidemiology
- M = F
- Mostly < 2 years of age
Sites
- Supratentorial in both hemispheres (70%)
- Infratentorial in cerebellum and brain stem (30%)
Clinical features
- Signs and symptoms of increased intracranial pressure (headache, nausea and visual disturbances)
- Focal neurologic signs (ataxia and weakness)
Grading
- WHO grade 4
Diagnosis
- Overexpression of LIN28A protein is highly sensitive and specific (Acta Neuropathol 2012;124:875)
Radiology description
- Contrast enhancing large tumor masses on CT and MRI
Case reports
- 33 month old boy with brainstem tumor (J Neurosurg Pediatr 2015;16:291)
Treatment
- Complete surgical removal, radiotherapy and high dose chemotherapy (J Neurooncol 2016;126:99, Childs Nerv Syst 2016;32:299)
Microscopic (histologic) description
- Biphasic architecture
- Dense clusters of small cells with round / polygonal nuclei, scanty cytoplasm and indistinct cell bodies along with large, paucicellular, fibrillary / neuropil like areas along with neoplastic neurocytic and ganglion cells
- Mitosis and apoptotic bodies in hypercellular area
- Multilayered rosettes
Positive stains
- Nestin and vimentin in neuroepithelium, multilayered rosettes and tubular structures
- Focal cytokeratins, EMA and CD99 in small cell areas
- INI1
- Ki67: 20% - 80%
Negative stains
Molecular / cytogenetics description
- Amplicon at 19q13.42 is sensitive and specific diagnostic marker for medulloepithelioma with C19MC alteration (Acta Neuropathol 2014;128:279)
- Embryonal tumor with abundant neuropil and true rosettes (ETANTR), ependymoblastoma and medulloepithelioma share molecular similarity and comprise a single clinicopathological entity
Ependymoblastoma, C19MC altered
Definition / general
Essential features
ICD coding
Epidemiology
Sites
Clinical features
Diagnosis
Radiology description
Case reports
Treatment
Gross description
Microscopic (histologic) description
Positive stains
Negative stains
Molecular / cytogenetics description
- Aggressive CNS embryonal tumor with multilayered rosettes (ETMR) and amplicon C19MC upregulation
- Rare tumor of children aged < 4 years
- Other tumors in this group are
- Embryonal tumor with abundant neuropil and true rosettes
- Medulloepithelioma
- References: Acta Neuropathol 2016;131:803, Acta Neuropathol 2014;128:305
Essential features
- Belongs to ETMR with or without alteration of C19MC, a new subclassification of embryonal tumors
- Rosettes are frequent and characteristic of embryonal tumors
- Ependymoblastoma lacks a neuropil-like matrix and ganglion cell elements
- Overexpression of LIN28A protein in C19MC altered embryonal tumors
- Poor prognosis
ICD coding
- ICD-O: 9478/3 - embryonal tumor with multilayered rosettes C19MC altered
Epidemiology
- M = F
- Mostly < 2 years of age
Sites
- Supratentorial in both hemispheres (70%)
- Infratentorial in cerebellum and brain stem (30%)
Clinical features
- Signs and symptoms of increased intracranial pressure (headache, nausea and visual disturbances)
- Focal neurologic signs (ataxia and weakness)
Diagnosis
- Overexpression of LIN28A protein (Acta Neuropathol 2012;124:875)
Radiology description
- Contrast enhancing large tumor masses on CT and MRI
Case reports
- 12 month old boy with embryonal tumor with multilayered rosettes of the fourth ventricle (J Neurosurg Pediatr 2015;16:579)
Treatment
- Complete surgical removal, radiotherapy and high dose chemotherapy (Childs Nerv Syst 2016;32:299)
Gross description
- Well circumscribed
- Grayish pink with areas of necrosis and hemorrhage
Microscopic (histologic) description
- Rosettes are frequent and characteristic of ETMR
- Sheets and clusters of poorly differentiated cells
- Lacks neuropil-like matrix and ganglion cells
- Rosettes are intermixed with small to medium sized embryonal cells with high N:C ratio
Positive stains
Negative stains
Molecular / cytogenetics description
- Amplicon at 19q13.42 is a sensitive and specific diagnostic marker for ETMR (Acta Neuropathol 2014;128:279)
Medulloepithelioma, C19MC not altered
Definition / general
Essential features
ICD coding
Epidemiology
Sites
Clinical features
Grading
Diagnosis
Radiology description
Case reports
Treatment
Microscopic (histologic) description
Positive stains
Negative stains
Molecular / cytogenetics description
- CNS embryonal tumor with prominent pseudostratified neuroepithelium that resembles the embryonic neural tube and poorly differentiated neuroepithelial cells
- Aggressive CNS embryonal tumor with multilayered rosettes (ETMR) and amplicon C19MC altered, C19MC unaltered or C19MC not tested
- Significant proportions of medulloepithelioma have not shown C19MC alterations (Acta Neuropathol 2016;131:803)
Essential features
- Belongs to ETMR, a new subclassification of embryonal tumors, some of which have C19MC alterations
- C19MC altered embryonal tumors overexpress LIN28A protein
- Poor prognosis
ICD coding
- ICD-10: C71.9 - malignant neoplasm of brain, unspecified
Epidemiology
- M = F
- Mostly < 2 years of age
Sites
- Supratentorial in both hemispheres (70%)
- Infratentorial in cerebellum and brain stem (30%)
Clinical features
- Signs and symptoms of increased intracranial pressure (headache, nausea and visual disturbances)
- Focal neurologic signs (ataxia and weakness)
Grading
- WHO grade 4
Diagnosis
- Overexpression of LIN28A protein is highly sensitive and specific (Acta Neuropathol 2012;124:875)
Radiology description
- Contrast enhancing large tumor masses on CT and MRI
Case reports
- 17 year old girl with unusual occurrence of supratentorial medulloepithelioma (J Neurosci Rural Pract 2014;5:261)
Treatment
- Complete surgical removal, radiotherapy and high dose chemotherapy (Strahlenther Onkol 2011;187:757, Childs Nerv Syst 2016;32:299)
Microscopic (histologic) description
- Neoplastic pseudostratified neuroepithelium resembling embryonic neural tube, with papillary, tubular and trabecular arrangements
- Sheets of poorly differentiated cells with hyperchromatic nuclei and high N:C ratio
- Multilayered rosettes may be seen
- Periodic acid-Schiff positive external limiting membrane
- No cilia or blepharoplasts on luminal surface of tubules
- Abundant mitotic figures
- Rarely mesenchymal differentiation and melanin pigment
Positive stains
- Patchy expression of cytokeratins and EMA in neuroepithelium
- Ki67 is high in embryonal cells
- Rare GFAP
- LIN28A
Negative stains
Molecular / cytogenetics description
- Amplicon at 19q13.42 is sensitive and specific diagnostic marker for medulloepithelioma with C19MC alteration (Acta Neuropathol 2014;128:279)