Pathology/Lab Coding Alert

Question: The pathologist evaluated slides from two blocks of a breast biopsy specimen. The exam included IHC for Her-2, reported as 3+ based on intensity and percentage of staining, and Ki67, reported as 36 percent [removed]cellular staining). For the same tissue, the pathologist also examined ER, PR, p40, and p63 stains. How should we code this?

Minnesota Subscriber

Answer: First, the correct code for the breast biopsy exam is 88305 (Level IV - Surgical pathology, gross and microscopic examination; … Breast, biopsy, not requiring microscopic evaluation of surgical margins …).

For the immunohistochemistry (IHC) slides, report the following:

• For the Her-2-neu and Ki67 quantitative or semiquantitative IHC, report two units of 88360 (Morphometric analysis, tumor immunohistochemistry (eg, Her-2/neu, estrogen receptor/progesterone receptor), quantitative or semiquantitative, per specimen, each single antibody stain procedure; manual) or 88361 (… using computer-assisted technology), depending on the method.
• For the estrogen receptor (ER), progesterone receptor (PR), p40, and p63 IHC stains, report one unit of 88342 (Immunohistochemistry or immunocytochemistry, per specimen; initial single antibody stain procedure) and 3 units of +88341 (… each additional single antibody stain procedure (List separately in addition to code for primary procedure)). You’ll need to append a modifier to these codes, such as 59 (Distinct procedural service), because they’re bundled as a column 2 code with 88360 and 88361 under National Correct Coding Initiative (NCCI) edits.

Medicare caveat: The NCCI Policy Manual states that “Immunohistochemistry reported with qualitative grading such as 1+ to 4+ shall be reported as CPT^® codes 88342, +88341, and 88344.” However, scoring systems such as 1+ to 4+ typically involve counting cells rather than just “qualitative grading”, which means that you should report the tests with 88360 or 88361. You’ve stated that the Her-2 procedure you use bases the score on intensity and percentage of staining, so you should be able to report the morphometric code. Check with your compliance officer and ensure that your documentation shows quantitation, and you should be able to ignore this controversial NCCI statement.

Unit of service: These codes state that the unit of service is the specimen. That means the number of blocks or slides is not relevant to your code selection. That’s different from some other stain codes, such as 88312 (Special stain including interpretation and report; Group I for microorganisms (eg, acid fast, methenamine silver)). Although the code descriptor doesn’t identify the unit of service, a note following the code states “Report one unit of 88312 for each special stain, on each surgical pathology block, cytologic specimen, or hematologic smear.”

Respect bundling: Don’t report 88342/+88341 in addition to 88360 or 88361 for the same IHC procedure. A CPT^® text note states “Do not report 88360, 88361 in conjunction with +88341, 88342, or 88344 unless each procedure is for a different antibody.” Your case does involve different antibodies, which is why you can bill the codes together with the appropriate modifier.