Pathology/Lab Coding Alert

Don't lose $90 for each additional antibody

When your lab uses an immunohistochemistry cocktail,do you bill for just one service? That could be right--or it could be costing you money.

You have to know when to report multiple units of CPT 88342 (Immunohistochemistry [including tissue immunoperoxidase], each antibody). If you get it wrong, you could be underbilling, or facing fraud charges for billing too much. The following expert tips will help you get your 88342 coding right every time.

Tip 1: Heed the code definition and bill per antibody

The 88342 description says, "each antibody," so you should report multiple units of the code if the lab performs more than one antibody stain on a single specimen, says Elizabeth Sheppard, HT(ASCP), marketing manager for Ventana Medical Systems in Tucson, Ariz.

For instance: The lab performs qualitative immunohistochemistry (IHC) for estrogen receptor (ER) and progesterone receptor (PR) on a breast biopsy specimen. The proper coding for the two stains is two units of 88342.
 
You should always be on the lookout for multiple units of 88342. "It's not unusual for a pathologist to evaluate a series of IHC antibody stains to assist in tumor typing, and you should list each stain as one unit of 88342," says Joan Logue, BS, MT(ASCP), principal with Health Systems Concepts Inc. in Longwood, Fla.

Ethically increase payment: Medicare's national limitation amount for the global 88342 service is $89.44. That's how much you stand to gain every time you correctly code 88342 for a separate IHC stain.

Tip 2: Count Different Colors in Cocktails

What if the lab uses an IHC "antibody cocktail"--a single stain that contains multiple histochemical antibodies? You should separately code each different-color antibody that the pathologist sees and assesses individually. As the College of American Pathologists stated in the June 2004 CAP Today, "If a specimen is stained with an antibody cocktail, report each antibody separately only if each one can be differentiated microscopically."

Example: Some antibody cocktails are commercially available, such as Biocare Medical's Double Vision IHC stains. If your lab uses one of these antibody cocktails, such as LCA + S100, you should charge two units of 88342, says Maria Teixeira, manager of technical support for Biocare Medical in Concord, Calif. "The Double Vision cocktails all result in two-color staining," Teixeira says. 

Avoid this hidden trap: If the stain involves multiple IHC antibodies that are not visually distinguishable, you should report only one unit of 88342, Teixeira says. For instance, you should not bill 88342 x 2 for cytokeratin stain AE1/AE3 even though you could consider it an antibody cocktail. This stain provides a single color to detect the presence of cells expressing both low and high molecular weight cytokeratins. Reporting 88342 x 2 for a cytokeratin stain would be fraudulent.

Tip 3: Don't be fooled by multiple blocks, slides

Sometimes you'll read a pathology report and see an IHC stain mentioned so many times that you're just sure you should report multiple units of 88342. Think again. If the pathologist only used one IHC stain, you can report only a single 88342, regardless of how many stained blocks or slides he reviewed.

Case in point: Sentinel lymph node biopsies often involve multiple blocks cut from different levels of the node and numerous sequential slides prepared from each block. "A sentinel lymph node biopsy might include multiple cytokeratin-stained slides taken from various levels of the excised tissue, but the exam only involves one antibody," Logue says. You should report this service as 88307 (Level V - Surgical pathology, gross and microscopic examination, sentinel lymph node), plus 88342 for the multiple cytokeratin stains.

Tip 4: Use 88342 for Qualitative IHC

Just because you see an IHC marker named in a pathology report doesn't mean you should automatically code 88342. Pathologists often use these same markers in tests that provide quantitative or semiquantitative results using either manual or automated methods. These services require different codes--88360 (Morphometric analysis, tumor immunohistochemistry [e.g., Her-2/neu, estrogen receptor/progesterone receptor], quantitative or semiquantitative, each antibody; manual) or 88361 (... using computer-assisted technology).

Only use 88342 for qualitative IHC antibody stains. Pathologists use these as "markers" for the presence or absence of specific antigens used to identify tumor type.  "The pathologist interprets these stains as 'yes,' the antigen is present, or 'no,' the antigen is not present, or may qualify based on stain intensity, without any quantification regarding the degree of staining," Logue says.

Lesson learned: To pick the correct code for IHC antibody markers, you have to know if the pathologist's exam was qualitative, quantitative/semiquantitative, and manual or automatic. For instance, the pathologist could evaluate slides for the presence or absence of estrogen receptor and progesterone receptor (qualitative, 88342 x 2).

Or the pathologist could quantify the ER/PR markers using manual morphometric analysis (88360 x 2). Either way, the report must reflect the evaluation method and findings.