MGMT methylation assessment in glioblastoma: MS-MLPA versus human methylation 450K beadchip array and immunohistochemistry

Purpose: The MGMT gene encodes a DNA repair enzyme that counteracts with chemotherapy efficiency, specifically with alkylating agents such as temozolomide (TMZ). It is well established that MGMT methylation should be screened as a predictive marker for TMZ in glioblastoma, and we thus aimed to determine a reliable and practical diagnostic method of MGMT methylation detection. Patients and methods: 55 glioblastomas were investigated for MGMT methylation status using methylation-specific multiplexed ligation probe amplification (MS-MLPA), illumina human methylation 450K BeadChip array (HM450 K) analysis, and compared to MGMT protein expression by immunohistochemistry (IHC) staining. The methylation status of promoter, intron and all MGMT CpG targeted sites were separately correlated to patient’s survival. Results: In addition to MS-MLPA and 450 K concordance, our results showed significantly higher overall survival (OS) of patients receiving TMZ and presenting MGMT methylated promoter (mean OS = 21.5 months, p = 0.046). Including all glioblastoma cases and regardless of chemotherapy, MS-MLPA showed significant survival difference between MGMT methylated and unmethylated cases (mean OS = 13, p = 0.021). Conclusion: We concluded that in glioblastoma, MGMT promoter methylation predicts TMZ sensitivity. This current comparative analysis leads to consider that MS-MLPA is a valuable as HM450 K array for MGMT methylation status screening (AU)

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MGMT methylation assessment in glioblastoma: MS-MLPA versus human methylation 450K beadchip array and immunohistochemistry.

PURPOSE: The MGMT gene encodes a DNA repair enzyme that counteracts with chemotherapy efficiency, specifically with alkylating agents such as temozolomide (TMZ). It is well established that MGMT methylation should be screened as a predictive marker for TMZ in glioblastoma, and we thus aimed to determine a reliable and practical diagnostic method of MGMT methylation detection. PATIENTS AND METHODS: 55 glioblastomas were investigated for MGMT methylation status using methylation-specific multiplexed ligation probe amplification (MS-MLPA), illumina human methylation 450K BeadChip array (HM450 K) analysis, and compared to MGMT protein expression by immunohistochemistry (IHC) staining. The methylation status of promoter, intron and all MGMT CpG targeted sites were separately correlated to patient's survival. RESULTS: In addition to MS-MLPA and 450 K concordance, our results showed significantly higher overall survival (OS) of patients receiving TMZ and presenting MGMT methylated promoter (mean OS = 21.5 months, p = 0.046). Including all glioblastoma cases and regardless of chemotherapy, MS-MLPA showed significant survival difference between MGMT methylated and unmethylated cases (mean OS = 13, p = 0.021). CONCLUSION: We concluded that in glioblastoma, MGMT promoter methylation predicts TMZ sensitivity. This current comparative analysis leads to consider that MS-MLPA is a valuable as HM450 K array for MGMT methylation status screening.

Adult recurrent pilocytic astrocytoma: Clinical, histopathological and molecular study.

BACKGROUND: PA is a grade I glial tumor that mostly occurs in children. However, although apparently similar to paediatric PA, adult PA presents a different clinical follow-up that could arise from specific molecular alterations. A variety of genetic alterations have been identified as diagnostic or prognostic glioma molecular markers. MATERIAL AND METHODS: We describe a right infratentorial tumor that occurred in a 58-year-old man. Neuroimaging and neuropathological examination suggested PA as an initial diagnosis. The tumor was completely resected. Unexpectedly, two years later, a rapidly growing tumor on the operative site was observed with a second location in the pineal region. Immunohistochemical reactions (IHC), Multiplex ligation probe amplification (MLPA) and fluorescence in situ hybridization (FISH) was performed in both primary and relapse tumor. RESULTS: Neuroimaging and neuropathological examinations suggested an unusual diagnosis for adult patients: a recurrent PA. Both MLPA and FISH analysis contribute to diagnostic confirmation by KIAA1549: BRAF fusion detection. Additional genetic results revealed interesting findings that justified the tumor aggressivity. CONCLUSION: Molecular analysis of adult PA cases should be routinely combined with histopathological and neuroimaging examination to further refine prognostic diagnoses.

Juvenile hyaline fibromatosis: a case report.

Juvenile hyaline fibromatosis is a rare, hereditary disease with distinct clinical and histopathological features. Clinically, it presents with gingival hypertrophy, pappulonodular skin lesions and joint contractures. Bone involvement is usually an uncommon finding. We report a case of a 2-year-old patient, daughter of consanguineous parents, who presented since the age of 2 months with impairment of mental development, multiple joint contractures, motion limitation and nodules on the scalp. The calvarian lesions were surgically removed, and histopathological examination concluded to juvenile hyaline fibromatosis.

MR imaging of intracranial hemangiopericytomas.

OBJECTIVE: To describe the MR features of primary intracranial hemangiopericytomas (HPCs) on conventional imaging, diffusion and MR spectroscopy and aim to determinate distinguishing features from meningiomas. METHODS: From 2006 to 2012, seven patients with pathologically confirmed primary intracranial HPCs were included. The clinical data, conventional MR findings (n=7), DWI features (n=7) and MR spectroscopy (n=5) were retrospectively analyzed. ADC values of the HPCs (n=7) were measured on ADC map and were compared with that of contralateral normal white matter. RESULTS: Of the seven HPCs, four were anaplastic HPCs (WHO grade III) and three were HPCs (WHO grade II). MR pattern consisted in lobulated or irregular margin tumors in all cases with cross-leaf growth on both side of the falx in two cases. The lesions showed mainly iso signal (n=4) on T1 WI and heterogeneous high signal (n=5) on T2 WI. Heterogenity was mainly related to intra tumoral hemorrhage (n=4), and proeminent intratumoral flow voids (n=3). Marked heterogeneous enhancement (n=5) with dural tail (n=4) was noted. All tumours showed significant peritumoral edema. ADC values of the tumor tissue component range between 0.638 and 1.50×10(-3)mm/s(2) (average = 1,02). Three grade II HPCs showed higher values compared to normal parenchyma ADC (range between 0.772 and 0.930×10(-3)mm/s(2) with average of 0.830), whereas grade III HPCs showed either equal (three cases) or decreased ADC values (one case). MRS showed in all cases markedly increased Cho with lip/lac peak, decreased Cr and almost absent NAA. High mI peak with large glutamine/glutamate were noted in the three grade II HPCs. CONCLUSION: Conventional MR pattern when combined with DWI and MRS findings are highly suggestive of HPC and appear valuable data to differentiate HPCs from meningiomas.

Cerebellar liponeurocytoma: case report.

Liponeurocytoma (lipomatous medulloblastoma) is a rarely and recently described tumor. We report an additional case of this uncommon lesion in an adult and we describe its clinical, radiological and histological features. A 45-year-old woman presented with symptoms and signs of increased intracranial pressure and cerebellar dysfunction. Computed tomography (CT) and magnetic resonance imaging (MRI) scans showed a heterogenous poorly circumscribed mass situated within the cerebellar vermis. After complete tumour resection, pathologic examination with immunohistochemical study confirmed the diagnosis. The postoperative course after 18 months was favorable with no evidence of tumor recurrence.

[Intradural and cervical primary malignant melanoma. Case report and review of the literature]. / Le mélanome malin primitif intra-dural et cervical. A propos d'un cas et revue de la littérature.

Primary malignant melanoma of the central nervous system is an uncommon localization, first reported by Hirsberg in 1906. Since then, to our knowledge, only 39 cases have been reported in the literature. We present a case of primary intradural extra-medullary melanoma which developed in a 51-Year-old man who complained of pain in the lower cervical spine, difficulties in micturition and sexual impotence. The diagnosis was suspected at the MRI which showed a lesion with a paramagnetic signal and was confirmed by the histological examination. The resection was complete and the course has been satisfactory after 19 months follow-up.