title: Molecular and genetic profiles of radiographically defined de novo meningiomas.
abstract: With the exception of radiation-induced tumors, benign meningiomas that are known to have developed within a defined time period are extremely rare. We have genetically characterized two cases of radiographically defined de novo, sporadic meningiomas--a 5-cm, left parasagittal tumor in a 61-year-old male and a 2.3-cm, right falx tumor in a 53-year-old female. Neither tumor was observed during MRIs performed for unrelated complaints 49 and 28 months before surgery, respectively. Both tumors were totally resected, and histopathological examination revealed WHO grade I meningiomas. In both cases, the MIB-1 staining indices were high for grade I meningioma (5.6% for case 1 and 9.1% for case 2), and abnormal accumulation of p53 were observed by immunohistochemistry. The two tumors shared losses of chromosome arms 1p and 7p by comparative genomic hybridization. The tumor suppressor merlin, product of the NF2 gene, was not detected in either tumor. These abnormalities found in common in both of the de novo meningiomas likely to play significant roles in the pathogenesis and/or rapid development of meningiomas. Moreover, taken together with previous studies, our findings indicate that the combined loss of 1p and 7p may play a critical role in the tumorigenesis of de novo, aggressive meningiomas.
authors.affiliation: Department of Neurosurgery, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Yohei
authors.initials: Y
authors.lastname: Kitamura
authors.forename: Hikaru
authors.initials: H
authors.lastname: Sasaki
authors.forename: Kazunari
authors.initials: K
authors.lastname: Yoshida
mesh_terms: D002878:Chromosomes, Human, Pair 1; D002897:Chromosomes, Human, Pair 7; D055028:Comparative Genomic Hybridization; D005260:Female; D005682:Gadolinium; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008577:Meningeal Neoplasms / Q000000981:diagnostic imaging* / Q000235:genetics*; D008579:Meningioma / Q000235:genetics* / Q000532:radiotherapy*; D008875:Middle Aged; D025581:Neurofibromin 2 / Q000235:genetics / Q000378:metabolism; D011859:Radiography; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism
chemical_list: D025581:Neurofibromin 2; D016159:Tumor Suppressor Protein p53; D005682:Gadolinium; C513496:MIB1 ligase, human; D044767:Ubiquitin-Protein Ligases