Summary & Overview
CPT 0578U: Merlin™ Test for Cutaneous Melanoma Risk Stratification
CPT code 0578U designates the Merlin™ Test, a proprietary PLA molecular diagnostic that evaluates gene expression in cutaneous melanoma to stratify risk of lymph node involvement and recurrence. As a single-manufacturer PLA code, 0578U identifies a specific 10-gene qPCR assay performed on FFPE tumor tissue and reported as low or high risk. Nationally, such PLA codes matter because they standardize billing and tracking for unique laboratory innovations used in cancer care and affect how payers and providers document and reimburse specialized molecular tests.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will learn the clinical context of the Merlin™ Test, where it is typically performed, and the implications of PLA coding for billing workflows. The publication summarizes payer coverage patterns and benchmarking where available, highlights relevant policy considerations for proprietary laboratory tests, and provides clinical context about test methodology and intended use in melanoma risk stratification. Data not available in the input are identified as such; the summary focuses on available national-level information rather than state-specific policies.
Billing Code Overview
CPT code 0578U is a Proprietary Laboratory Analyses (PLA) code that applies exclusively to the Merlin™ Test from SkylineDx USA Inc. The Merlin™ Test evaluates cutaneous melanoma tissue for gene activity associated with risk of lymph node involvement and recurrence. The assay measures expression of 10 genes using real–time quantitative polymerase chain reaction (qPCR) on a formalin–fixed paraffin–embedded (FFPE) tumor sample and reports a result indicating low or high risk for nodal metastasis and recurrence.
Service type: Laboratory molecular diagnostic test (proprietary gene expression assay)
Typical site of service: Clinical laboratory or pathology/laboratory service associated with oncology or dermatopathology; specimen collected from outpatient dermatology or surgical oncology setting and processed in a certified laboratory.
Clinical & Coding Specifications
Clinical Context
A 62-year-old patient with a recently excised primary cutaneous melanoma undergoes pathologic staging. The surgical pathology report shows intermediate Breslow depth and/or other adverse features prompting assessment for risk of lymph node involvement and recurrence. The treating dermatologic surgeon or surgical oncologist requests the Merlin™ Test (0578U) on the formalin‑fixed paraffin‑embedded (FFPE) tumor block. The specimen is shipped to SkylineDx USA Inc.; the laboratory performs real‑time qPCR on a 10‑gene panel and reports a binary risk result (low vs high) that informs decisions about sentinel lymph node biopsy, postoperative surveillance intensity, and multidisciplinary care planning. Typical site of service includes an outpatient hospital laboratory or independent clinical reference laboratory; specimen collection and surgical excision occur in an ambulatory surgical center or hospital outpatient setting. Common modifiers applied to billing include 00 (default), 22 (increased procedural services), 52 (reduced services), and 53 (discontinued procedure) depending on reporting circumstances.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
00 | No modifier / default submission | Use when no special circumstances apply and full service is rendered. |
22 | Increased procedural services | Use when work or resources required to process the specimen are substantially greater than typical for the test (rare for PLA tests, requires documentation). |
52 | Reduced services | Use when part of the test or processing is intentionally reduced or not completed yet still reported. |
53 | Discontinued procedure | Use when the test order is cancelled after initiation of processing and reporting of a discontinued service is appropriate. |
26 | Professional component | Use if the reporting laboratory separates professional interpretation from technical testing and the professional component is billed separately. |
TC | Technical component | Use if the technical component (laboratory processing) is billed separately from professional interpretation. |
90 | Reference (outside) laboratory | Use when the performing laboratory is a reference lab and billing is submitted by a different entity that used an outside lab. |
91 | Repeat clinical diagnostic laboratory test | Use when the exact same test is repeated on the same day and repeat reporting rules apply. |
AZ | Laboratory designation (manufacturer-specific PLA reporting when required) | Use when payer requires manufacturer/lab-specific designator for a PLA test (payer-specific application). |
| Taxonomy Code | Specialty | Notes |
|---|---|---|
| 207P00000X | Dermatology | Dermatologists diagnose and manage cutaneous melanoma and may order the Merlin™ Test. |
| 208000000X | General Surgery | Surgical oncologists or general surgeons perform excisions and sentinel node procedures and may order testing for staging. |
| 2086S0122X | Surgical Oncology | Specialists involved in melanoma surgical management and ordering tumor molecular tests. |
| 208000000X | Pathology | Pathologists oversee specimen handling, confirm diagnosis, and coordinate molecular send-outs. |
| 261QM0800X | Clinical Laboratory | Clinical laboratory specialists and directors in reference labs perform and bill for the PLA assay. |
Related Diagnoses
| ICD-10 Code | Description | Clinical Relevance |
|---|---|---|
C43.9 | Malignant melanoma of skin, unspecified | Primary diagnosis for which the Merlin™ Test (0578U) is ordered to assess recurrence and nodal risk. |
C43.7 | Malignant melanoma of lower limb, including hip | Site-specific melanoma frequently evaluated with molecular prognostic assays. |
C43.4 | Malignant melanoma of scalp and neck | Lesions with variable behavior where additional prognostic information may guide management. |
D03.9 | Melanoma in situ, unspecified | Occasionally used when margins or deeper invasion are uncertain and molecular risk stratification is considered. |
C43.3 | Malignant melanoma of lower limb, including hip | (Alternative site-specific code) Indicates tumor location relevant to staging and management decisions. |
Related CPT Codes
| CPT Code | Description | Relationship to This Procedure |
|---|---|---|
88304 | Level IV surgical pathology, gross and microscopic examination | Performed on excision specimens prior to molecular testing; provides histopathologic diagnosis and tissue selection for 0578U. |
88305 | Level V surgical pathology, gross and microscopic examination | Used for more complex pathology evaluation of melanoma specimens that may precede molecular testing. |
88342 | Immunohistochemistry, each antibody (if performed) | IHC stains may be used adjunctively to characterize tumor and select tissue for molecular assay. |
88360 | Morphometric analysis (special staining/analysis) | Applied when additional tumor measurements or special analyses are performed prior to molecular testing. |
99000 | Handling and/or conveyance of specimen for transfer between facilities (example code) | Administrative/handling charges may be billed when specimens are sent to a reference lab for 0578U (payer rules vary). |