Pathology/Lab Coding Alert

Question: Our hospital lab has an arrangement with a local dermatologist to perform tissue histology. The dermatologist decided to excise a suspected squamous cell carcinoma on the vermilion border of the lower lip in layers to preserve the integrity of healthy skin. The dermatologist submitted one layer, which our pathologist diagnosed and reported “margins not clear” to the dermatologist during surgery. The dermatologist excised and submitted a second layer, which the pathologist also determined and reported “margins not clear.” The dermatologist submitted a third layer, which the pathologist reported “margins clear,” and received no more specimens from that patient. Should we code his as a Moh’s procedure since it involved layered excision?

California Subscriber

Answer: Even though the physician removed the lesion layer-by-layer, you should not report this using Mohs codes, such as 17311(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) (eg, hematoxylin and eosin, toluidine blue), head, neck, hands, feet, genitalia, or any location with surgery directly involving muscle, cartilage, bone, tendon, major nerves, or vessels; first stage, up to 5 tissue blocks).

To report Mohs, the physician needs to work as both the surgeon and the pathologist. In this case, your pathologist performed only the tissue examination, not the lesion excision.

Because the pathologist immediately prepared and diagnosed slides from the excisions and reported the findings back to the dermatologist, he most likely processed the specimens as frozen sections. In that case, you should report the service using the following codes:

• 88331 (Pathology consultation during surgery; first tissue block, with frozen section(s), single specimen)
• And two units of +88332 (… each additional tissue block with frozen section(s) (List separately in addition to code for primary procedure)).