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Type:
Educational Exhibit
Keywords:
Neuroradiology brain, CNS, Oncology, MR, CT, Diagnostic procedure, Neoplasia
Authors:
R. Gomes Marques; Lisbon/PT
DOI:
10.1594/ecr2015/C-2350
Background
Meningothelial tumors or meningiomas belong to a broad group of extra-axial intracranial neoplasms named meningeal tumors and arise from the arachnoid cap cell that are believed to be of neural crest origin.
Meningiomas are the most common intracranial neoplasm with a incidence of 2.6 per 100.000 in general population and represent 25% of all new brain tumor diagnoses per year.
Their female preponderance is not present in pediatric and young adults meningiomas.
The etiology of meningiomas is multifactorial,
including genetic factors and local irradiation.
Viral particles,
namely from papovaviruses e adenovirus DNA,
are found in genetic material of meningiomas,
which provides circumstantial evidence for an etiologic role in their growth.
In World Health Organization (WHO) 2007 revision of brain tumor taxonomy meningiomas were classified in three categories according to the histologic atypia,
histologic subtypes and e biological agressivity (brain invasion):
• Benign-WHO grau I (80-90%): includes subtypes meningothelial,
fibroblastic,
transitional,
psammomatous,
microcystic,
lymphoplasmacytic,
angiomatous,
secretory e metaplastic.
• Atypical-WHO grau II (8-10%): includes subtypes chordoid and clear cell.
• Malignant-WHO grau III (1-2%) includes subtypes rhabdoid and papillary.
Imaging studies (CT and MR) are fundamental in the diagnose and identification of signs suggestive of a more aggressive biological behavior.