Summary & Overview

CPT 81341: T‑cell Receptor Beta (TCRB) Clonality Analysis, Direct Probe

CPT code 81341 represents a specialized molecular diagnostic laboratory procedure that detects abnormal clonal T‑cell populations by analyzing the T‑cell antigen receptor beta (TCRB/TRB@) using direct probe methods such as Southern blot. This test is clinically important because detection of T‑cell clonality can support the diagnosis and classification of certain leukemias and lymphomas, informing prognosis and downstream diagnostic pathways.

Key payers in the national coverage landscape include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an overview of clinical context for use of this assay, common sites of service (clinical and reference laboratories), and a summary of billing and coding considerations relevant to laboratory and pathology departments. The publication also outlines available benchmarks for utilization and reimbursement patterns where available, highlights policy updates affecting molecular and pathology testing, and explains how this code fits within molecular diagnostic service lines.

This summary is written for a national audience and focuses on clinical relevance, payer coverage contours, and the operational implications for laboratory services. Data not available in the input: associated taxonomies, ICD‑10 diagnoses, related codes, and specific utilization benchmarks.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicare81341CPTmolecular-diagnosticspathologyt-cell-clonalitysouthern-blotlaboratoryhematology-oncology

Billing Code Overview

CPT code 81341 describes a laboratory test that detects abnormal clonal T‑cell populations by analyzing the T‑cell antigen receptor, beta (TCRB or TRB@) using direct probe methods such as Southern blot. The service is a molecular pathology / specialized diagnostic laboratory procedure performed by a lab analyst or molecular technologist to identify clonal T‑cell populations that may indicate certain leukemias or lymphomas.

Service Type: Specialized molecular diagnostic laboratory test (direct probe T‑cell receptor analysis)

Typical Site of Service: Clinical laboratory or reference molecular pathology laboratory

Clinical & Coding Specifications

Clinical Context

A 62-year-old patient with persistent lymphadenopathy, unexplained cytopenias, and B symptoms (fever, night sweats, weight loss) is referred by hematology-oncology for molecular clonality testing to evaluate suspected T-cell lymphoma. Peripheral blood and/or lymph node tissue is submitted to the molecular diagnostics laboratory. The laboratory technologist performs DNA extraction and applies 81341 testing using direct probe methods (for example, Southern blot) to detect abnormal clonal T‑cell populations involving the T‑cell receptor beta locus (TCRB/TRB@). The laboratory issues a report describing presence or absence of clonal rearrangements, which contributes to diagnostic classification, staging, and treatment planning. Typical site of service is an independent or hospital-based clinical molecular pathology laboratory or reference lab. The service type is molecular pathology / targeted clonality testing. The clinical workflow includes specimen accessioning, nucleic acid extraction, probe hybridization (Southern blot or equivalent direct probe method), autoradiography or chemiluminescent detection, result interpretation by a molecular pathologist, and final reporting to the ordering hematologist/oncologist.

Coding Specifications

Modifier	Description	When to Use
`26`	Professional component	Use when billing only the professional interpretation and report by the pathologist or molecular physician.
`TC`	Technical component	Use when billing only the technical component (laboratory processing and testing) performed by the facility or reference lab.
`90`	Reference (outside) laboratory	Use when the service was performed by an outside laboratory and billed by the ordering provider as paid to another lab.
`59`	Distinct procedural service	Data not available in the input.
`77`	Repeat procedure by another physician	Data not available in the input.
`52`	Reduced services	Use when the service is partially reduced or limited compared with full `81341` testing.
`53`	Discontinued procedure	Use if testing was started but discontinued due to technical failure or insufficient specimen.
`QX`	Ordering/performing laboratory correct coding modifier	Use when the ordering/performing laboratory relationship is reported under applicable CLIA rules (when applicable vendor-specific modifiers are required).
`QY`	Ordering/servicing laboratory link	Use where an ordering/servicing laboratory relationship is documented under local coverage rules.
`90`	Duplicate of above; reference lab maintained	Data not available in the input.

Taxonomy Code	Specialty	Notes
207RH0000X	Hematopathology	Hematopathologists interpret clonality testing and integrate results with morphologic and flow cytometry data.
2080P0227X	Molecular Genetic Pathology	Laboratories specializing in molecular diagnostic testing for hematologic malignancies.
2085R0201X	Clinical Laboratory	Technical laboratories performing molecular assays and Southern blot techniques.
207K00000X	Anatomic and Clinical Pathology	Pathologists responsible for ordering and interpreting specialized clonality studies.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`C84.0`	Mycosis fungoides	T‑cell clonality testing supports diagnosis when cutaneous T‑cell lymphoma is suspected.
`C84.4`	Peripheral T‑cell lymphoma, unspecified	Molecular evidence of clonal T‑cell receptor rearrangement aids in confirming peripheral T‑cell lymphoma.
`C91.0`	Acute lymphoblastic leukemia, T‑cell type	Clonality testing can identify T‑cell lineage and support diagnosis and minimal residual disease assessment.
`C83.3`	Diffuse large B‑cell lymphoma, immunoblastic type	Included when evaluating differential diagnoses; T‑cell clonality testing helps exclude T‑cell origin.
`R59.0`	Localized enlarged lymph nodes	Indication for biopsy and subsequent clonality testing when malignant etiology is suspected.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`81275`	Immunoglobulin heavy chain (IGH) gene rearrangement analysis; for clonality assessment	Performed alongside T‑cell receptor tests to evaluate B‑cell clonality when differential includes B‑cell lymphoma.
`81445`	Oncology (hematologic/somatic) gene analysis by NGS, larger panels	May be ordered subsequently for broader mutational profiling if clonality testing supports malignancy.
`88312`	Special stains (e.g., immunohistochemistry)	Used on tissue biopsy specimens to correlate molecular clonality with immunophenotype.
`86336`	Immunoassay for tumor markers (e.g., flow cytometry panels reported separately)	Flow cytometry is commonly performed before or alongside molecular clonality testing to define immunophenotype.
`81273`	T-cell receptor gamma (TCRG) gene rearrangement analysis	Frequently ordered with `81341` to increase sensitivity for detecting clonal T‑cell populations.