Pathology/Lab Coding Alert

Question: Please explain if we should use Mohs codes for the following case, or if not, how we should code the case.

The surgeon submits the following tissue to our pathologist for examination from a Mohs-type procedure:

First stage: Initial skin tumor tissue that the surgeon submits as four separate specimens, A, B, C, and D. The pathologist performs frozen section exam on one block from each specimen, and paraffin-embedded tissue exam on one block from each specimen except “A,” which requires two blocks.

Second stage: Based on frozen section results of first stage showing remaining tumor, surgeon submits shaving of skin tumor site A, and pathologist performs intraoperative frozen section and later permanent section exam.

Third stage: Based on results of second stage that margins were not clear, the surgeon submits another shaving of skin tumor site A, with intraoperative frozen section and permanent section exam by the pathologist.

Texas Subscriber

Answer: You should not use the Mohs codes (17311-17315, Mohs micrographic technique, including removal of all gross tumor, surgical excision of tissue specimens, mapping, color coding of specimens, microscopic examination of specimens by the surgeon, and histopathologic preparation including routine stain[s] [e.g., hematoxylin and eosin, toluidine blue]…) for this work. A true Mohs procedure involves one physician acting as both the surgeon and the pathologist. Because this case involves a surgeon submitting the stages to a pathologist, you should use the 80000 level codes to describe your pathologist’s work.

For the first stage, A, B, C, and D each represent a separate, uniquely-identified specimen, which impacts your coding. You should report four units of 88331 (Pathology consultation during surgery; first tissue block, with frozen section[s], single specimen), one for each initial block from each specimen. Because the pathologist doesn’t examine a separate frozen-section block from any of the specimens, you have no need of 88332 (…each additional tissue block with frozen section[s] [List separately in addition to code for primary procedure]) in this case.

You should also separately report the permanent tissue exam for each specimen, which means four units of 88305 (Level IV - Surgical pathology, gross and microscopic examination Abortion,… Skin, other than cyst/tag/debridement/plastic repair…). You shouldn’t separately bill additional blocks for a surgical pathology exam, so quadrant A earns just one unit of 88305 even though the pathologist examines two blocks.

The second and third stages each warrant one unit of 88331, and one unit of 88305.

Bottom line: Bill the case as 88331 x 6, and 88305 x 6.