Browsing by Subject "Meningiomas"

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    Next generation sequencing identifies novel potential actionable mutations for grade I meningioma treatment
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2020) Pepe, Francesco; Pisapia, Pasquale; Del Basso de Caro, Maria Laura; Conticelli, Floriana; Malapelle, Umberto; Troncone, Giancarlo; Martinez, Juan Carlos
    Meningiomas are common brain tumors that arise from the meningeal membranes that envelope the brain and spinal cord. The World Health Organization classifies these tumors into three histopathological grades. Because of tumor recurrence, treating meningiomas may be challenging even in well- differentiated grade I (GI) neoplasms. Indeed, around 5% of completely resected GI meningiomas relapse within 5 years. Therefore, identifying driver mutations in GI meningiomas through next generation sequencing (NGS) assays is paramount. The aim of this study was to validate the use of the 50-gene AmpliSeq Hotspot Cancer Panel v2 to identify the mutational status of 23 GI meningioma, namely, 12 non recurrent and 11 recurrent. In 18 out of the 23 GI meningiomas analyzed, we identified at least one gene mutation (78.2%). The most frequently mutated genes were c-kit (39.1%), ATM (26.1%), TP53 (26.1%), EGFR (26.1%), STK11 (21.7%), NRAS (17.4%), SMAD4 (13%), FGFR3 (13%), and PTPN11 (13%); less frequent mutations were SMARCB1 (8.7%), FLT3 (8.7%), KRAS (8.7%), FBWX7 (8.7%), ABL1 (8.7%), ERBB2 (8.7%), IDH1 (8.7%), BRAF (8.7%), MET (8.7%), HRAS (4.3%), RB1 (4.3%), CTNNB1 (4.3%), PIK3CA (4.3%), VHL (4.3%), KDR (4.3%), APC (4.3%), NOTCH1 (4.3%), JAK3 (4.3%), and SRC (4.3%). To our knowledge, mutations in all of these genes, except for TP53, STK11, SMARCB1, PIK3CA, VHL, and BRAF, have never been described before in meningiomas. Hence, these findings demonstrate the viability of NGS to detect new genetic alterations in GI meningiomas. Equally important, this technology enabled us to detect possible novel actionable mutations not previously associated with GI and for which selective inhibitors already exist
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    Primary ectopic meningiomas: Report of 6 cases with emphasis on atypical morphology and exploratory immunohistochemistry
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2022) Ni, Hao; Yang, Qianqian; Shi, Chenxi; Zhao, Peiyu; Zhan, Shenghua; Guo, Lingchuan
    Aims. To investigate the histological and immunohistochemical features of primary ectopic meningiomas (PEMs), especially those of primary ectopic atypical meningiomas (PEAMs). Methods and results. We examined 6 cases of PEM, including 2 PEAM cases, which occurred separately in left nasal cavity, left lower lung, right neck, left orbit, right upper lung, and left upper lung by histological and immunohistochemical analysis. In general, of the 6 PEM cases analyzed, 4 cases exhibited morphology of Grade I, including 1 fibrous, 1 meningothelial, and 2 transitional variant. The remaining 2 cases shared similar atypical morphology of Grade II. The tumors were distributed in sheet-like patterns with loss of architecture of classic meningiomas. Significant hypercellularity, multi-focal necrosis, and thin-walled blood vessels were identified. The mitotic figures were estimated at 6 per 10 high-power fields in one case, and 8 mitotic figures in another. Immunohistochemically, the 6 PEM cases were all positive for Vimentin and EMA, while none showed immunostaining for CKpan, S-100, CD34, STAT6, SMA, Syn or Bcl-2. 4 PEM cases of Grade I were immunoreactive for PR but negative for P53, while the 2 PEAM cases displayed negative staining for PR but positivity for P53. As for Ki-67, the positive staining of 4 Grade I cases was no greater than 2%, while the positive rates of the 2 PEAM cases were 10% and 20%. Conclusions. Our study has expanded cases of PEMs, especially the 2 PEAM cases in rare sites. Our study has also further summarized the pathological features of PEMs, focusing on the histological features of PEAMs, and the immunohistochemical features worthy of further investigations