Pathology/Lab Coding Alert

Question: Should we bill a prostate triple stain as 88342 or 88342 x 3?

Florida Subscriber

Answer: You should list the service as 88342 x 3 (Immunohistochemistry [including tissue immunoperoxidase], each anibody).

Reasoning: The unit of service for 88342 immunostains is the "antibody," and the prostate triple stain (also called PIN4) contains three antibodies. For instance the stain typically uses p504S (also called AMCAR), p63, and CK903 (a highmolecular weight cytokeratin). Each of the three stains provides unique diagnostic information, as opposed to "mixing" to form a single diagnostic entity.

For instance: The p504 stains cytoplasm red in prostate adenocarcinoma, while p63 stains basal cell nuclei brown in benign prostate glands or prostatic intraepithelial neoplasia (PIN). The high molecular weight cytokeratin also helps identify basal cells in benign and PIN specimens by staining the cytoplasm brown.

Best documentation: To support reporting 88342 x 3, the pathologist should mention the diagnostic contribution of each stain in the pathology report. Doing so makes clear that the three stains contribute individually to the diagnosis.

Code per block for Medicare: Although CPT stipulates that the unit of service for surgical pathology is the specimen, Medicare's Correct Coding Initiative (CCI) Policy Manual version 15.3 (effective Oct. 1, 2009) states that the unit of service for 88342 is the block. If it is medically reasonable and necessary for the pathologist to examine the PIN4 stain on more than one prostate biopsy specimen or block, you should report 88342 x 3 for each specimen or block.

Reader Questions and You Be the Coder were prepared with the assistance of R.M. Stainton Jr., MD, president of Doctors' natomic Pathology Services in Jonesboro, Ark.