Pathology/Lab Coding Alert

Question: The lab receives a paraffin-fixed specimen for T-cell receptor (TCR) gene rearrangement assay to aid in diagnosing T-cell malignancy. The lab lyses cells from the paraffin-embedded tissue, extracts purified DNA and amplifies genes from the V and J regions of the T-cell receptor gamma chain gene. The process involves amplification of two separate nucleic acid sequences and multiplex reactions to amplify 24 other sequences in a single tube. The lab then uses high-resolution capillary electrophoresis to evaluate the amplified genes and report on the presence of a TCR-gamma clonal expansion that might suggest T-cell malignancy. What is the correct coding for this service?

Maryland Subscriber

Answer: You-ve described a molecular diagnostics study, which you should report using appropriate codes for each step of the analysis from the code range 83890-83914 (Molecular diagnostics ...).

Code the scenario this way: For lymph-node cell lysis prior to DNA extraction, report 83907 (- lysis of cells prior to nucleic acid extraction [e.g., stool specimens, paraffin embedded tissue]). Report the extraction as 83891 (- isolation or extraction of highly purified nucleic acid).

List 83898 (- amplification of patient nucleic acid, each nucleic acid sequence) x 2 for amplifying the two individual gene sequences. Also report 83900 (- amplification of patient nucleic acid, multiplex, first two nucleic acid sequences) plus +83901 (- amplification of patient nucleic acid, multiplex, each additional nucleic acid sequence [list separately in addition to code for primary procedure]) x 22 for the multiplex reactions.

Use 83909 (- separation and identification by high resolution technique [e.g., capillary electrophoresis]) to code for the high-resolution identification technique.

The lab should not code for the pathologist's interpretation (83912, - interpretation and report) if an independent pathologist interprets the results.

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