Pathology/Lab Coding Alert

Question: I-m preparing to establish a flow cytometry panel that includes NK cells, B cells, T cells (CD4 and CD8 plus ratio), CD2 and CD20. The CPT immunology section has specific codes for the first three but not for CD2 and CD20. Should I code those using the flow cytometry codes 88184 and 88185?


Virginia Subscriber


Answer: Labs may use flow cytometry methods for total cell counts to evaluate immune dysfunction or for immunophenotyping of hematolymphoid cancers. CPT provides two sets of codes for these flow cytometry tests, and you should not mix codes from the two groups when reporting a panel.

The immunology section lists codes you-d use for a panel designed to assess an immunodeficiency or similar condition. These panels do not normally require a pathologist's interpretation. The panel you describe appears to be for assessing immune dysfunction, so you should use the following codes:

- 86357 -- Natural killer (NK) cells, total count

- 86355 -- B cells, total count

- 86360 -- T cells; absolute CD4 and CD8 count,  including ratio. For the CD2 and CD20, which CPT does not list with specific codes, report two units of 86586, Unlisted antigen, each.

You should not use the nonspecific flow-cytometry codes 88184 (Flow cytometry, cell surface, cytoplasmic, or nuclear marker, technical component only; first marker) and +88185 (- each additional marker [list separately in addition to code for first marker]) for the CD2 and CD20 in this panel.

When you perform flow cytometry studies for immunophenotyping of hematolymphoid cancers, use 88184-88189 to report the service. Codes 88184 and 88185 describe the technical service associated with performing the flow cytometry. Then you must also report an interpretation code for each study based on the number of codes in the panel, such as 88187 (Flow cytometry, interpretation; 2 to 8 markers).