Pathology/Lab Coding Alert

You'll have to choose between CPT 88358 and 88182

More than one code describes a DNA ploidy study for tumor analysis, so how can you choose the correct code? First you'll have to know how the pathologist performs the study. But you'll also need to learn Medicare's coding rules for DNA ploidy -- CMS has restrictions that aren't in the code definition.

CPT 2004 added DNA ploidy to the code definition for 88358 (Morphometric analysis; tumor [e.g., DNA ploidy]), but that doesn't mean it's the only code you should use to report a tumor DNAploidy study. The code describes a specific method -- morphometric analysis -- which is image-analysis microscopy.

Coding example: The pathologist stains slides from a prostate resection with Feulgen blue, and then uses ChromaVision Automated Cellular Imaging System (ACIS) to digitally analyze cellular DNA ploidy in the context of a DNA histogram. "Use 88358 to report this service," says Joan Logue, BS, MT-ASCP, principal with Health Systems Concepts Inc. in Longwood, Fla.

If the pathologist conducts DNAploidy using a flow cytometer, you should report the service as 88182 (Flow cytometry; cell cycle or DNA analysis), according to Dennis Padget, MBA, CPA, FHFMA, president of DL Padget Enterprises Inc., a pathology business publishing company in Simpsonville, Ky.

Although flow cytometry does not determine the actual chromosome number (ploidy), pathologists may use the procedure to describe total DNA content and quantify an aneuploid peak that has diagnostic significance for tumor. "The AMA's CPT Information Services unit recently confirmed that you should report DNAploidy according to method -- flow cytometry as 88182 versus other methods as 88358," Padget says.

You'd never know from the 88358 definition that you shouldn't use the code for a manual image analysis DNA ploidy study -- but you shouldn't, according to CMS. The National Correct Coding Initiative (NCCI) policy manual states that you should use CPT 2004 revised-code 88358 for "DNA ploidy and S-phase analysis of tumor by digital cellular imaging technique."

Caution: CMS restricts your use of 88358 even more. Although the code definition lists DNA ploidy as an example of the morphometric tumor analysis procedure, the NCCI policy manual states that you should not use 88358 "to report any service other than DNA ploidy and S-phase analysis." (The manual is available on the Internet at http://www.cms.hhs.gov/physicians/cciedits/chap10.pdf.)

"Medicare's code interpretation is not surprising," Logue says. "CMS sometimes interprets parenthetic examples in CPT code definitions as the limiting factor for the code."

Tip: One unit of service for 88358 includes both DNA ploidy and S-phase analysis, according to CMS.