Pathology/Lab Coding Alert

Question: Our lab performs qualitative EGR and PIN-4 stains on a single prostate core biopsy of a prostate biopsy case. Can we bill for both stains since they’re on a single core, and if so, what codes should we use? 

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Answer: Yes, you can report multiple, unique, qualitative IHC stains on a single specimen, even if it’s the same prostate biopsy core, which is part of a prostate biopsy case that entails several cores. 

In this case, the two stains you describe are qualitative immunohistochemistry (IHC) stains. One is an IHC stain for EGR, and the correct code for that stain is 88342 (Immunohistochemistry or immunocytochemistry, per specimen; initial single antibody stain procedure). 

The PIN-4 stain, often called a prostate triple stain, is actually a multiplex stain. That means the lab analyst applies more than one antibody stain to a slide, which the pathologist can distinctly visualize and interpret to provide unique diagnostic information. For instance, a PIN-4 stain often includes p504S, which stains adenocarcinoma cytoplasm red; P63, which stains basal cell nuclei brown in prostatic intraepithelial neoplasia (PIN); and CK903, which stains basal cells in benign and PIN specimens. The correct code for a qualitative multiplex IHC stain is 88344 (... each multiplex antibody stain procedure). 

Caution: Because 88342 is a column 2 code bundled with 88344 according to the Correct Coding Initiative (CCI), you’ll need use an appropriate modifier to unbundle the codes, such as 59 (Distinct procedural service) or XU (Unusual non-overlapping service). Overriding the edit pair is appropriate in this case, because you are billing the two codes for distinct antibody stains on the same specimen.