Posted Date
Effective Date
Update Type New Tests
CPT Code 81479, G0452-26
Order Code NMETH



Neuropathology Methylation Array

Order Code:                  NMETH

Fee Code:                     NA122

CPT Code:                    81479, G0452-26


The MLabs Molecular Diagnostics Laboratory will begin offering a Neuropathology Methylation Array assay beginning August 31, 2022.


This methylation profiling assay is intended to provide supplementary information for the diagnosis and should be interpreted only 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.


Collection Instructions: 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.