Fluorescence in situ hybridization (FISH) for chromosome 14q deletion in subsets of meningioma segregated by MIB-1 labelling Index

Noopur Gupta, (2014) Fluorescence in situ hybridization (FISH) for chromosome 14q deletion in subsets of meningioma segregated by MIB-1 labelling Index. Masters thesis, Christian Medical College, Vellore.

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Abstract

OBJECTIVE: To correlate histopathological grading of meningiomas segregated into subgroups based on the MIB-1 labelling index with chromosomal loss of 14q using Fluorescence in situ hybridisation (FISH). METHODS: 46 cases were segregated into five categories based on the MIB-1 labelling index (MIB-1 LI) as <5%, 5-7.5%, 7.5-9.9%, 10% and >10%. Slides of all cases were reviewed to ascertain the grade and to look for the presence of histopathological features for atypia. Immunohistochemical staining for MIB-1 was performed using a Ventana Benchmark XT Autostainer. Commercially available FISH paraffin pre-treatment kit and SpectrumOrange fluorophore labelled probe against telomeric region of 14q (Abbott Molecular: Vysis TelVysion) were used. The observer reporting 14q status was blinded to the MIB-1 LI. Subsequently, correlation between 14q deletion and MIB-1 LI was studied. RESULTS: There were 21 WHO grade I, 24 grade II and 1 grade III meningiomas. There was a statistically significant difference between the mean duration of symptoms, average maximum dimension and the MIB-1 LI of grade I and grade II meningiomas. 33.3% grade I cases showed 14q deletion, when compared to 84% of grade II and III meningiomas (p=0.000). Amongst the histological parameters for diagnosis of atypical meningioma, hypercellularity, small cell formation, prominent nucleoli and sheet like growth were significantly associated with 14q deletion. All brain invasive meningiomas (n = 6) had 14q deletion. As MIB-1% increased, the prevalence of deletions was significantly higher (p<0.01). The mean MIB-1 of the 7 grade I meningiomas that had 14q deletions was 8.86±1.95% when compared to 4.14±1.35% for those without 14q deletions. CONCLUSION: A strong association existed between histologic grade, MIB-1 LI and the presence of chromosome 14q deletion. Association of high MIB-1 LI with 14q deletions even in meningiomas with a Grade I histology defines a distinct subset of benign meningiomas. The biological behaviour of this subset needs further exploration with follow-up studies for recurrence and aggressive behaviour.

Item Type: Thesis (Masters)
Additional Information: Reg.No.20111955
Uncontrolled Keywords: Meningioma, WHO grade, MIB-1, 14q deletion, Fluorescence in situ hybridization (FISH).
Subjects: MEDICAL > Pathology
Depositing User: Subramani R
Date Deposited: 23 Mar 2020 16:45
Last Modified: 17 Aug 2020 06:10
URI: http://repository-tnmgrmu.ac.in/id/eprint/12440

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