Pathology/Lab Coding Alert

Question: For a 31-year-old female patient, our pathologist examined a breast lumpectomy case and diagnosed invasive lobular carcinoma with clear margins. The lab also completed a ChromaVision automated cellular imaging system for ER/PR on tissue from two blocks from the lumpectomy specimen, with ER/PR 20-40 percent positive results. How should we report the procedures and diagnosis?

Ohio Subscriber

Answer: Report the pathologist’s lumpectomy exam as 88307 (Level V - surgical pathology, gross and microscopic examination, breast, excision of lesion, requiring microscopic evaluation of surgical margins).

For the quantitative estrogen receptor/progesterone receptor (ER/PR) immunohistochemistry, report two units of 88361 (Morphometric analysis, tumor immunohistochemistry (eg, Her-2/neu, estrogen receptor/progesterone receptor), quantitative or semiquantitative, per specimen, each single antibody stain procedure; using computer-assisted technology). Despite testing tissue from two blocks, the unit of service for the code is “per specimen,” so you shouldn’t code per block.

Why 2 units? Even though you can’t code per block, you should code 88361 for each single antibody stain procedure. That means you can code 88361 for the ER test, and 88361 for the PR test.

Watch diagnosis: Invasive lobular carcinoma is a malignant breast neoplasm, so you should list the primary diagnosis as C50.91 (Malignant neoplasm of breast of unspecified site, female). If the pathology report provides more-specific information about the site of the excised lump, you should report a more specific code such as C50.411 (Malignant neoplasm of upper-outer quadrant of right female breast).

You should also report the ER-positive findings as Z17.0 (Estrogen receptor positive status [ER+]). A note following this code states, “Code first malignant neoplasm of breast (C50.-)), so make sure you don’t report Z17.0 as the primary diagnosis.