Embryonal tumor with abundant neuropil and true rosettes: Morphological, immunohistochemical, ultrastructural and molecular study of a case showing features of medulloepithelioma and areas of mesenchymal and epithelial differentiation
ABSTRACT Embryonal tumors are a group of malignant neoplasms that most commonly affect the pediatric population. Embryonal tumor with abundant neuropil and true rosettes is a recently recognized rare tumor. It is composed of neurocytes and undifferentiated neuroepithelial cells arranged in clusters, cords and several types of rosettes in a prominent neuropil-rich background. We describe a new case of this tumor. The patient, a 24-month-old female infant, was referred to the Meyer Children's Hospital with a history of right brachio-crural deficit associated with occasional episodes of headache and vomiting. Computed tomography scan and MRI revealed a large bihemispheric mass. The patient underwent two consecutive surgeries. The resultant surgical resection of the tumor was macroscopically complete. The postoperative period was uneventful. On light microscopy the tumor showed a composite morphology: embryonal tumor with abundant neuropil and true rosettes (specimen from the first surgery); medulloepithelioma with mesenchymal and epithelial areas (specimen from the second surgery). The immunohistochemistry evidenced the heterogeneous (neuronal, mesenchymal and epithelial) immunoprofile of tumoral cells. By real-time polymerase chain reaction (RT-PCR), the PTEN gene expression in the tumor was lower than in the five non-neoplastic brain tissues used as control. Mutation analysis did not show any variation in INI-1 and PTEN sequence while P53 analysis showed the presence of homozygote P72R variation. Fluorescent in situ hybridization analysis showed polysomy of chromosome 2 while amplification of N-MYC was not detected. Owing to the rarity of embryonal tumor with abundant neuropil and true rosettes, each new case should be recorded to produce a better clinical, pathological and molecular characterization of this lesion.
- SourceAvailable from: Vineeta Vijay Batra[Show abstract] [Hide abstract]
ABSTRACT: Embryonal tumor with abundant neuropil and true rosettes (ETANTR) is a rare variant of central nervous system primitive neuroectodermal tumor occurring exclusively in the pediatric population. We report a unique case of a 6-month male child presenting with a large intraventricular lesion. Histological examination revealed a tumor composed of primitive neuroectodermal cells in dense aggregates, interspersed by hypocellular areas containing small round cells widely dispersed in neuropil-like material. Few ependymal and occasional ependymoblastic rosettes were appreciated. Focal melanotic neuroepithelium recapitulating retinal differentiation was also seen. Documentation of such cases may expand the neuroectodermal differentiation spectrum of ETANTR.Fetal and pediatric pathology 05/2013; 32(6). DOI:10.3109/15513815.2013.799250 · 0.40 Impact Factor
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ABSTRACT: Embryonal central nervous system (CNS) tumors are currently classified into three types: medulloblastoma, atypical rhabdoid/teratoid tumors, and primitive neuroectodermal tumor (PNET). A distinctive subtype of PNET called "embryonal tumor with abundant neuropil and true rosettes" (ETANTR) was reported in 2000. ETANTR is a recently described variety of PNET that combines microscopic features of neuroblastoma and ependymoblastoma, demonstrating areas of fine fibrillary neuropil intermingled with cellular zones and ependymoblastic rosettes. It has been suggested that this neoplasm should be considered as a separate entity. ETANTR is an eminently pediatric tumor that has been reported exclusively in children younger than 4 years. ILLUSTRATIVE CASES: A 9-month-old girl underwent subtotal resection of a brainstem neoplasm. A 23-month-old girl was submitted to surgery for a frontoparietal tumor. In both instances, the histopathological diagnosis confirmed ETANTR. Both children were treated with chemotherapy and one with radiotherapy. Death in both patients occurred after a mean period of 10 months. By reporting these two new instances of ETANTR, we want to contribute to the knowledge of this highly malignant CNS embryonal neoplasm that occurs only in young children, given its present lethal prognosis, the scarcity of reported cases, and the lack of treatment guidelines.Child s Nervous System 05/2010; 26(8):1003-8. DOI:10.1007/s00381-010-1179-x · 1.16 Impact Factor
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ABSTRACT: Ependymoblastoma (EBL) and embryonal tumor with abundant neuropil and true rosettes (ETANTR) are very aggressive embryonal neoplasms characterized by the presence of ependymoblastic multilayered rosettes typically occurring in children below 6 years of age. It has not been established whether these two tumors really comprise distinct entities. Earlier, using array-CGH, we identified a unique focal amplification at 19q13.42 in a case of ETANTR. In the present study, we investigated this locus by fluorescence in situ hybridization in 41 tumors, which had morphologically been diagnosed as EBL or ETANTR. Strikingly, FISH analysis revealed 19q13.42 amplifications in 37/40 samples (93%). Among tumors harboring the amplification, 19 samples were identified as ETANTR and 18 as EBL. The three remaining tumors showed a polysomy of chromosome 19. Analysis of recurrent/metastatic tumors (n = 7) showed that the proportion of nuclei carrying the amplification was increased (up to 80-100% of nuclei) in comparison to the corresponding primary tumors. In conclusion, we have identified a hallmark cytogenetic aberration occurring in virtually all embryonal brain tumors with ependymoblastic rosettes suggesting that ETANTR and EBL comprise a single biological entity. FISH analysis of the 19q13.42 locus is a very promising diagnostic tool to identify a subset of primitive neuroectodermal tumors with distinct morphology, biology, and clinical behavior.Acta Neuropathologica 08/2010; 120(2):253-60. DOI:10.1007/s00401-010-0688-8 · 9.78 Impact Factor