Summary & Overview
CPT 82387: Cathepsin-D Tumor Tissue Protein Assay
CPT code 82387 designates a laboratory assay that measures cathepsin–D levels on cell lysates from tumor-derived tissue. Cathepsin–D is an intracellular protease; clinicians order this test primarily to obtain prognostic information for breast cancer and other malignancies. As a specialized tumor tissue protein assay, the code matters nationally because results can influence clinical prognostication, research datasets, and laboratory billing for oncology pathology services.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of the clinical context for 82387, typical sites of service, and the role of the assay in oncology pathology. The publication summarizes common payer considerations, billing modifiers provided in the input, and typical laboratory service line placement.
This report offers practical benchmarks and policy-relevant context: how the test is classified in procedure coding, where it is usually performed, and why cathepsin–D measurement is clinically significant. Data not available in the input is noted where applicable. The content is intended for revenue cycle, laboratory operations, and clinical stakeholders seeking a clear, national-level briefing on CPT code 82387 and its use in tumor prognostic assessment.
Billing Code Overview
CPT code 82387 measures cathepsin–D levels in cell lysates derived from tumor tissue. The test quantifies an intracellular protease, cathepsin–D, to provide prognostic information for breast cancer and other tumor types. This assay is performed on tissue-derived samples prepared as cell lysates and reported as a laboratory pathology service.
Service Type: Laboratory — tumor tissue protein assay
Typical Site of Service: Hospital pathology laboratory, independent clinical laboratory, or cancer center laboratory
Clinical & Coding Specifications
Clinical Context
A 56-year-old woman with a newly diagnosed invasive ductal carcinoma of the right breast presents after core needle biopsy and surgical excision. The oncology team requests tumor biomarker testing, including measurement of intracellular cathepsin-D from tumor tissue lysates to provide prognostic information that may influence adjuvant therapy planning. The specimen is a formalin-fixed, paraffin-embedded tumor block or fresh frozen tumor sample obtained in the surgical pathology laboratory. The pathology assistant or histology technician prepares cell lysates from microdissected tumor tissue and the clinical laboratory scientist performs the quantitative assay for cathepsin-D. Results are reported to the ordering oncologist and entered in the electronic medical record as part of the tumor profile used for multidisciplinary treatment planning.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | When billing for the professional interpretation/analysis of the assay separate from the technical laboratory processing. |
TC | Technical component | When billing for the laboratory technical component (reagents, instrumentation, technician time) separate from professional interpretation. |