Test Overview
Methylation Array
This methylation profiling assay is intended to provide supplementary information for the diagnosis and should only be interpreted by a qualified neuropathologist. In neuro-oncology, several studies have illustrated that methylation profiling enables the classification of neurological neoplasms with greater precision and greater reliability than is achievable by morphologic, immunophenotypic and clinical means alone. When used in conjunction with traditional pathologic methods, methylation profiling results in reclassification of a significant proportion of cases (approximately 10-12%), many of which also altered WHO grading which would result in significantly different patient management. In addition, methylation profiling has enabled the discovery and subsequent diagnosis of new neoplastic entities with distinct biology, clinical behavior, and potential management.
Interpretive report provided.
* Reference ranges may change over time. Please refer to the original patient report when evaluating results.
This methylation profiling assay is intended to provide supplementary information to aid in diagnosis. Correlation with histopathologic and clinical findings by a qualified neuropathologist is required for a final, integrated diagnosis. A negative result does NOT exclude the presence of a neoplasm as the limit of detection varies widely among the different neoplasms classifiable by this assay.
Test Details
12-20 days
Specimen Requirements
The Neuropathology Methylation Array (NMETH) assay is not available for stand-alone ordering by MLabs clients. Please submit a consultation request using the MLabs Anatomic Pathology Consultation requisition and indicate NMETH in the Additional Instructions section. If the NMETH is needed to further assess the patient’s tissue following an MLabs consultation, please send slides and block and reference the previous MLabs consultation case number.
For formalin-fixed, paraffin-embedded tissue, a block containing an area with a high percentage of neoplastic cells (for micro-/macro-dissection) is preferred. Unstained, UNBAKED slides (5-8, 10-micron slides; 10-15 if few neoplastic cells are present on each level) with associated H&E stained slide are also acceptable. Decalcified tissue or other fixatives will be accepted, and the assay attempted; however, this specimen type may result in failed testing due to degraded nucleic acid. Both blocks and slides should be stored at room temperature. A Diff-Quik or Papanicolaou stained aspirate smear (preferable containing a high percentage and overall amount of neoplastic cells is also acceptable; however, extraction will result in destruction of the slide(s). A digital image of the slide(s) must be collected prior to extraction and retained for a minimum of 10 years from the specimen collection date. Store at room temperature.
Previously extracted DNA from a CLIA certified laboratory may be accepted; however, the extracting laboratory must take responsibility for ensuring that there are adequate viable, neoplastic cells within the extracted sample.
Additional Information
By ordering this test the clinician acknowledges that informed consent has been obtained from the patient as required by applicable state or federal laws and the ordering clinician has authorization from the patient permitting MLabs to report the test results to the ordering clinician. Test includes microdissection billed as a separate additional charge. Test includes pathologist interpretation of results billed as a separate additional charge. This test is not available without interpretation.