CPT 0338U: CELLSEARCH HER2 Circulating Tumor Cell (CTC–HER2) Test

CPT code 0338U designates a Proprietary Laboratory Analyses (PLA) test — the CELLSEARCH® HER2 Circulating Tumor Cell (CTC–HER2) Test from Menarini Silicon Biosystems Inc. This noninvasive blood-based assay identifies, isolates, and counts HER2-positive circulating tumor cells to aid clinical management of patients with breast cancer. As a PLA code, 0338U applies to a single manufacturer-specific test and carries implications for coding, billing, and coverage discussions nationwide.

Key payers in the national analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an overview of clinical context for HER2 CTC testing, typical sites of service, and the implications of PLA designation for proprietary assays. The publication also summarizes payer coverage patterns, benchmark payment considerations, and recent policy developments affecting laboratory PLA codes.

This resource is intended to inform billing teams, laboratory managers, and policy analysts about the clinical role of the CELLSEARCH® HER2 CTC test, where it is performed, and which major payers are relevant for coverage conversations. Data not available in the input are noted where applicable in detailed sections.

Billing Code Overview

CPT code 0338U is a Proprietary Laboratory Analyses (PLA) code that applies exclusively to the CELLSEARCH® HER2 Circulating Tumor Cell (CTC–HER2) Test from Menarini Silicon Biosystems Inc. The test is a noninvasive laboratory assay that uses a specialized instrument to identify, isolate, and count HER2-positive circulating tumor cells (CTCs) from a peripheral blood specimen to support management of patients with breast cancer.

Service Type: Laboratory diagnostic test (proprietary PLA assay)

Typical Site of Service: Clinical laboratory or hospital laboratory receiving peripheral blood specimens for specialized testing

Clinical Context

A 58-year-old woman with a history of HER2-negative primary breast cancer presents with rising tumor markers and new symptoms suggestive of metastatic progression. Her oncologist orders a noninvasive circulating tumor cell HER2 assay to evaluate HER2 expression on circulating tumor cells (CTCs) to inform potential targeted therapy decisions when tissue biopsy is infeasible or to monitor treatment response. A peripheral blood specimen (usually 7.5 mL) is drawn in an outpatient oncology clinic or phlebotomy center and transported to the laboratory performing the proprietary CELLSEARCH® HER2 CTC test. The laboratory uses the specific Menarini Silicon Biosystems instrument and reagents to enrich, identify, and count HER2-positive CTCs. Results are returned to the ordering oncologist and integrated into the patient’s management plan, possibly prompting confirmatory tissue testing or changes in systemic therapy.

Coding Specifications

Modifier	Description	When to Use
`00`	Default, no modifier	Use when no special circumstances apply to the service
`26`	Professional component	Use when billing only the professional interpretation component (if applicable and separately reportable)

Taxonomy Code	Specialty	Notes
`207RH0000X`	Hematology & Oncology	Ordering and interpreting oncologists who manage breast cancer patients
`2086P0800X`	Medical Oncology	Specialists who integrate CTC HER2 results into systemic therapy decisions
`261QM0800X`	Clinical Pathology	Laboratory directors responsible for test validation and reporting
`207L00000X`	Surgical Oncology	Surgeons who may order testing when tissue access is limited or for perioperative planning

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`C50.911`	Malignant neoplasm of unspecified site of right female breast	Common primary diagnosis for patients undergoing HER2 CTC testing to evaluate metastatic disease or therapeutic targets
`C50.912`	Malignant neoplasm of unspecified site of left female breast	Same clinical relevance for left-sided primary breast cancer
`C78.7`	Secondary malignant neoplasm of liver and intrahepatic bile ducts	Representative metastatic site prompting systemic evaluation including CTC testing
`C79.81`	Secondary malignant neoplasm of brain	Metastatic progression where noninvasive assays may complement imaging and tissue diagnosis
`Z85.3`	Personal history of malignant neoplasm of breast	Surveillance context where CTC HER2 testing may be used to monitor recurrence risk or profile disease

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`36415`	Collection of venous blood by venipuncture	Commonly performed immediately prior to the CELLSEARCH® HER2 CTC assay to obtain the peripheral blood specimen
`99000`	Handling and/or conveyance of a specimen for transfer from the office to a laboratory	Used when specimen transport services are billed separately by some payors or facilities
`88360`	Morphological examination of cells in fluid or washings, including interpretation and report (cytologic)	May be performed for complementary cytologic analysis when tissue or fluid cytology is obtained alongside CTC testing
`86336`	Immunoassay for tumor marker (e.g., HER2) — Note: general immunoassay code	Occasionally used in parallel laboratory workflows for other HER2-related assays; not a substitute for the PLA code
`0001U`	Example PLA test code (placeholder)	PLA codes for other proprietary tests may be performed in panels or as sequential tests in complex diagnostic workflows

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Summary & Overview