Pathology/Lab Coding Alert

Question: As part of a partial mastectomy case, the surgeon submits a separate container with a single lymph node labeled “sentinel node.” Should we bundle this and use the total mastectomy code that includes regional lymph nodes, or should we separately report a lymph node biopsy?

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Answer: You should not bundle the lymph node with the breast specimen to code a total mastectomy (88309, Level VI - Surgical pathology, gross and microscopic examination … Breast, mastectomy – with regional lymph nodes …). Nor should you separately report the single node as a lymph node biopsy (88305, Level IV - Surgical pathology, gross and microscopic examination … Lymph node, biopsy …).

The correct coding for the case would be to report the partial mastectomy as 88307 (… Breast, mastectomy – partial/ simple…) and separately code the sentinel lymph node exam as an additional unit of 88307 (…Sentinel lymph node…).

Distinction: A sentinel lymph node biopsy is distinct from a lymph node biopsy, which is why CPT® provides separate codes for the pathology exam. The surgeon will identify the sentinel node as the first node into which the tumor drains. If the sentinel node is clear, it indicates that the cancer has not metastasized. Sentinel lymph node findings may impact the clinician’s treatment decisions for the patient.

A sentinel node pathology exam typically requires far more work than a regular lymph node biopsy exam. The pathologist will process multiple paraffin blocks and serially section each block. The procedure often involves antibody staining on multiple sections from each block. In this way, the pathologist thoroughly examines the single node at all levels throughout the tissue to ensure detection of any metastasis, if present.

Add-on: Don’t forget to separately code the antibody special stain(s) that the pathologist documents using the following codes:

• 88342 (Immunohistochemistry or immunocytochemistry, per specimen; initial single antibody stain procedure)
• +88341 (… each additional single antibody stain procedure (List separately in addition to code for primary procedure))

Because the code definition states, “per specimen,” you should not report multiple units for each stained slide from multiple blocks. Instead, report only 88342 if the pathologist documents a single antibody stain, but also add +88341 for each unique antibody stain that the pathologist documents.