Pathology/Lab Coding Alert

Question: Our pathologists use a billing template to check off what tests were done, fill in the diagnosis, and submit for billing. As a coder, I read the report and match the billing before submitting. For HER2/NEU ISH testing, the template has printed 88367 x 2. When the report reads, "HER2 by FISH," is this 88367 or 88367 x 2?

New Jersey Subscriber

Answer: Assuming that the HER2/NEU test methodology is in situ hybridization (ISH) with automated counting (computer assisted), you should report two units of 88367 (Morphometric analysis, in situ hybridization [quantitative or semi-quantitative] each probe; using computer-assisted technology).

Per probe: The code definition states, "each probe," and the HER2/NEU by fluorescence ISH (FISH) requires two probes. A common test procedure uses DNA probes, which are small segments of fluorescent DNA material. In a process called "hybridization," one probe that fluoresces green attaches specifically to chromosome 17 (where the HER2 gene resides), and another that fluoresces orange attaches specifically to the HER2 gene itself. Using a fluorescence microscope and computer-assisted image analysis, the pathologist quantifies the ratio of chromosome-17 fluorescence and HER2 gene fluorescence to see if the ratio is 1:1 (normal).

If there is an increase in HER2 gene fluorescence, indicating gene overexpression, the result is a significant predictor of tumor recurrence and an aid in assessing the patient for treatment with HERCEPTIN® (Trastuzumab).

Coding: Because the test involves two DNA probes, you should report two units of 88367 for this HER2/NEU FISH analysis.