FISHing for 1p19q codel in oligodendroglioma.
Malays J Pathol
; 42(3): 369-376, 2020 Dec.
Article
in En
| MEDLINE
| ID: mdl-33361717
ABSTRACT
Together with isocitrate dehydrogenase (IDH) mutation, co-deletion of 1p19q (1p19q codel) is a prerequisite for diagnosis of oligodendroglioma, making it imperative that histopathology laboratories introduce testing for 1p19q codel. To date there is still no consensus reference range and cut-offs that confirm deletion of 1p or 19q. We embarked on determining our reference range in 11 formalinfixed, paraffin-embedded non-neoplastic brain tissue using fluorescence in situ hybridisation (FISH) with the Vysis 1p36/1q25 and 19q13/19p13 FISH Probe Kit (Abbott Molecular Inc., USA). At same time we attempted to validate our methodology in 13 histologically-confirmed IDH-mutant oligodendrogliomas. For 1p, percentage cells with deletion (range=8-23%; mean±SD = 15.73±5.50%) and target control (1p361q25) ratio (range = 0.89-0.96; mean±SD = 0.92±0.03) in non-neoplastic brain, differed significantly (p<0.000) from oligodendroglioma (percentage cells with deletion range = 49-100%; mean±SD = 82.46±15.21%; targetcontrol ratio range0.50-0.76; mean±SD = 0.59±0.08). For 19q, percentage cells with deletion (range = 7-20%; mean±SD = 12.00±3.49%) and targetcontrol (19q13/19p13) ratio (range0.90-0.97; mean±SD = 0.94±0.02) in non-neoplastic brain also differed significantly from oligodendroglioma (percentage cells with deletion range = 45-100%; mean±SD = 82.62±18.13%; targetcontrol ratio range0.50-0.78; mean±SD = 0.59±0.09). Using recommended calculation method, for diagnosis of 1p deletion, percentage of cells showing deletion should be >32-33% and/or targetcontrol ratio <0.83. For 19q, percentage of cells showing deletion should be >22% and targetcontrol ratio <0.88. Using these cut-offs all 13 oligodendroglioma demonstrated 1p19q codel.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Oligodendroglioma
/
Chromosomes, Human, Pair 1
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Brain Neoplasms
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In Situ Hybridization, Fluorescence
Limits:
Adolescent
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Adult
/
Aged
/
Female
/
Humans
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Male
/
Middle aged
Language:
En
Journal:
Malays J Pathol
Year:
2020
Document type:
Article
Affiliation country: