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**Overview**: Low-Grade Glioma IHC FISH Panel**Introduction**: The Low-Grade Glioma IHC FISH Panel is a diagnostic tool designed to diagnose low-grade glioma using FFPE tissue. In India, low-grade gliomas (WHO grade 2, diffuse astrocytoma/oligodendroglioma) account for ~15-20 percent of primary brain tumors (~20,000-25,000 new CNS tumors/year), with molecular markers (IDH1/2 mutation, 1p/19q codeletion) defining prognosis and guiding therapy (better survival with IDH-mutant/1p19q-codeleted tumors). High morbidity from under-testing in rural/low-SES patients with seizures/headache, limited neuropathology/IHC/FISH labs, delayed accurate subtyping leading to inappropriate radiotherapy/chemotherapy or missed targeted options. Per neuro-oncology practices aligned with ICMR and Indian Society of Neuro-Oncology guidelines, the test employs microscopy, IHC, FISH, and PCR for 9 markers (IDH1 R132H, IDH2, 1p/19q codeletion, ATRX, p53, Ki-67, etc.) over 1-2 days with high accuracy, valuable for integrated WHO classification. This diagnostic falls under cancer screening and targets patients with suspected low-grade glioma on MRI, addressing accurate detection to guide observation, surgery, or temozolomide/PCV. With elevated morbidity due to underdiagnosis, the test supports public health efforts by enabling precise molecular subtyping and improving glioma outcomes. Its FFPE-based approach ensures reliable tissue-based analysis.**Other Names**: Glioma IHC FISH Pnl.**FDA Status**: FDA approved, CLIA certified for molecular pathology/histopathology/oncology, compliant with 2025 standards.**Historical Milestone**: IDH/1p19q testing standard since 2016 WHO update; in India, expanding in neuro-oncology centers.**Purpose**: The test assesses 9 parameters including IDH1 to guide low-grade glioma diagnosis, molecular subtyping, inform prognosis/therapy.**Test Parameters**: 1â€"9. IHC/FISH Markers (IDH1, IDH2, 1p/19q, etc.).**Pretest Condition**: No fasting required; patients should have brain lesion biopsy.**Specimen**: Formalin-fixed paraffin-embedded block (0.5â€"2 cm³), transported within specified times to maintain sample integrity.Sample Stability: Indefinite when properly stored in formalin/paraffin; testing possible long-term.**Medical History**: Patients should provide details on seizures, headache, MRI findings.**Consent**: Written informed consent is required, detailing the test's purpose, potential risks of inaccurate subtyping including wrong therapy, benefits of molecular profiling, and no additional discomfort (uses existing block).**Procedural Considerations**: The test involves slide preparation, IHC/FISH/PCR by trained personnel to ensure accurate scoring, avoid artifacts, and provide detailed report within 1-2 days using provided controls. Laboratories must maintain a controlled environment, adhere to quality assurance protocols.**Factors Affecting Result Accuracy**: Poor fixation, inadequate tumor content, or interpretation differences can affect results. Correlation with clinical evaluation or additional testing is recommended to confirm findings.**Clinical Significance**: IDH-mutant + 1p/19q codeleted indicates oligodendroglioma (favorable), necessitating specialist input.**Specialist Consultation**: Neuro-oncologists/neurosurgeons should be consulted for management.**Additional Supporting Tests**: MRI, NGS for confirmation.**Test Limitations**: Dependent on block quality; comprehensive approach required.**References**: Indian Journal of Pathology 2024, Neuro-oncology Studies India 2023. |
