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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
Author(s) -
Buccoliero Anna Maria,
Castiglione Francesca,
Degl'Innocenti Duccio Rossi,
Franchi Alessandro,
Paglierani Milena,
Sanzo Massimiliano,
Cetica Valentina,
Giunti Laura,
Sardi Iacopo,
Genitori Lorenzo,
Taddei Gian Luigi
Publication year - 2010
Publication title -
neuropathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.701
H-Index - 61
eISSN - 1440-1789
pISSN - 0919-6544
DOI - 10.1111/j.1440-1789.2009.01040.x
Subject(s) - neuropil , pathology , neuroepithelial cell , biology , immunohistochemistry , synaptophysin , polysomy , in situ hybridization , embryonic stem cell , medicine , central nervous system , gene , genetics , gene expression , neuroscience
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.