Summary & Overview
CPT 81524: CNS Tumor DNA Methylation Profiling
CPT code 81524 represents a specialized laboratory test for DNA methylation profiling of central nervous system (CNS) tumors. The assay interrogates methylation at over 10,000 genomic sites and applies algorithmic classification against reference tumor families and classes, reporting a probability score for tumor type and, when performed, MGMT promoter methylation status to inform likely chemotherapy response. Nationally, this test matters for precision diagnosis of CNS neoplasms, guiding tumor classification, prognosis, and potential treatment decisions.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an overview of clinical context for methylation-based CNS tumor classification, typical service and site-of-service considerations, and what to expect in payer coverage approaches. The publication summarizes benchmarks where available, highlights relevant policy updates affecting laboratory reimbursement and clinical utilization, and outlines common coding and billing considerations tied to laboratory tumor profiling services.
This summary is intended for a national audience of payers, health system leaders, laboratory directors, and clinicians involved in neuro-oncology diagnostics.
Billing Code Overview
CPT code 81524 describes a laboratory-based genomic methylation profiling test performed on DNA from central nervous system (CNS) tumor tissue. The assay measures DNA methylation at more than 10,000 sites across the genome and uses one or more algorithms to compare the patient tumor profile to reference tumor families and classes, producing a probability score for tumor classification. When performed, the test also evaluates methylation of the MGMT gene promoter to help predict response to certain chemotherapies.
Service Type: Laboratory genomic tumor profiling using DNA methylation arrays and computational classification
Typical Site of Service: Clinical laboratory or reference molecular pathology laboratory, using surgically obtained or biopsy CNS tumor tissue as the specimen source.
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Clinical & Coding Specifications
Clinical Context
A 55-year-old patient presents with a newly diagnosed intracranial mass following MRI with contrast that shows a contrast-enhancing supratentorial lesion. Neurosurgery obtains CNS tumor tissue at craniotomy and submits formalin-fixed paraffin-embedded (FFPE) tumor tissue to a reference molecular pathology laboratory. The laboratory performs high-density genome-wide DNA methylation profiling using an assay that evaluates methylation at >10,000 CpG sites and applies a validated classifier algorithm to compare the tumor’s methylation profile to reference tumor families and classes. The reported output includes a calibrated probability score for tumor class assignment and may include MGMT promoter methylation status to assist oncologists in chemotherapy decision-making. Typical clinical workflow: tissue accessioning and QC → DNA extraction and bisulfite conversion → array- or sequencing-based methylation assay → bioinformatic processing with classifier algorithm(s) → pathologist review and integrated report returned to ordering neurosurgeon/neuro-oncologist. Typical site of service: hospital inpatient or outpatient surgical center for tissue acquisition with subsequent testing performed at a reference commercial or academic molecular pathology laboratory. Typical service type: high-complexity molecular diagnostic laboratory test (molecular pathology / genomic classifier report). Typical patient scenarios include tumor classification when histology is ambiguous, subclassification of gliomas or other CNS tumors, or when ancillary information (MGMT promoter methylation) influences adjuvant therapy planning.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 |