Pathology/Lab Coding Alert

A CPT text note following the codes states, "For flow cytometric immunophenotyping for the assessment of potential hematolymphoid neoplasia, see 88182, 88184-88189." (Except the note following 86587 specifies, "see 88182, 88189.")

Same Cell Markers Used for Immunology, Neoplasm Immunophenotyping

Physicians may order B cell, NK cell, or stem cell studies for disparate reasons, such as to monitor immune response in HIV patients or to assess potential hematolymphoid neoplasia in cancer patients. To select the proper code, you need to know why the physician ordered the test and whether the pathologist interprets the results for neoplasia immunophenotyping.

"Depending on whether the lab performs immunologic tests for these cells to evaluate conditions such as immunodeficiency, or performs flow-cytometry cell analysis to aid in cancer diagnosis, you should report the cell studies using a different set of codes in the CPT book - immunology in the 86000s, and flow cytometry in the 88000s," says William Dettwyler, MT-AMT, president of Codus Medicus, a laboratory coding consulting firm in Salem, Ore.

Clinical Lab Fee Schedule Pays Immunology Codes

Labs often perform clinical cell analyses to evaluate immunodeficiency using test kits or immunologic methods that may involve flow cytometry. These tests don't require an interpretive report. "That's when you should use 86000 codes, such as T cells (86359, T cells; total count), B cells (86064), NK cells (86379), or stem cells (86587)," Dettwyler says.

Medicare will pay for new codes 86064, 86379, and 86587 under the Clinical Laboratory Fee Schedule (CLFS), and the agency has crosswalked the codes to existing CPT 86359 . That means you'll see about $52.70 (National Fee Cap) for each B cell, NK cell, or stem cell test. Because these are CLFS codes, they represent a technical clinical-lab service with no separately billable professional component for test-result interpretation.

Physician Fee Schedule Pays Flow Cytometry Codes

Pathologists often evaluate a series of cell markers using flow cytometry to type and classify different types of lymphomas and leukemias - and that's when you should use the flow cytometry codes.

Example: The pathologist may interpret a leukemia panel that involves 10 markers including CD34 (stem cells) and B cells.

Old way: Before CPT 2005 introduced new flow cytometry codes, you may have reported this service as 88180 x 10 (deleted in 2005: 88180, Flow cytometry; each cell surface, cytoplasmic or nuclear marker). "If the panel contained markers that were listed in the 86000 codes, such as T cells, you may have reported all of the unlisted markers as 88180, but the listed total T cells as 86359," Dettwyler says.

New way: Using new codes introduced in CPT 2005, you should now report the first marker as 88184 (Flow cytometry, cell surface, cytoplasmic, or nuclear marker, technical component only; first marker), plus +88185 x 9 (... each additional marker [list separately in addition to code for first marker]) for the technical work involved in other the nine markers in the panel.

"Additionally, you should report 88188 (Flow cytometry, interpretation; 9-15 markers) for the pathologist's professional interpretation of the panel," says Laurie Castillo, CPC, CPC-H, CCS-P, owner of Castillo Consulting in Manassas, Va.

Even though CPT 2005 provides immunology codes for CD34 (stem cells, 86587) and B cells (86064), you should not use those codes for the panel in this example. "The text note following these codes indicates that you shouldn't report a mixture of flow cytometry and specific cell-type immunology codes for a flow cytometry panel that the pathologist interprets to assess lymphoid neoplasia," Dettwyler says. "Instead, you should use the new flow cytometry codes to report the entire panel."

Note: For a complete list of the new flow cytometry codes, see the table in "Keep Up With the 2005 CPT Code Changes" on pages in this issue.