Q&A: Selecting a Follow-up Excision Code

Question: A patient had a biopsy done at another facility by a different provider. The biopsy showed squamous cell carcinoma, and our dermatologist performed a further excision to obtain clear margins at that site. The path report for this follow-up excision came back as actinic keratosis. Would the proper CPT® coding be 11603 (based on the original diagnosis of squamous cell carcinoma) or 11403 (based on the follow-up result of actinic keratosis)?
Answer: Under most circumstances, you absolutely cannot use the “malignant” code and/or diagnosis unless the malignancy has been confirmed by pathology. In this case, however, the previous excision and biopsy did confirm this, and the re-excision was done to obtain clear margins. The assumption is that both the diagnosis and procedure code are for the malignancy.
Per the May 2012 CPT Assistant, even if the subsequent pathology comes back with a different diagnosis, the further excision should be linked to the original (malignant) diagnosis:
In general, the selection of the appropriate excision code is determined by three parameters: location, maximum excised diameter (which includes the margin), and lesion type (ie, benign or malignant). When the lesion is clearly benign (eg, cyst, lipoma, prior biopsy of benign neoplasm), the excision can be coded as benign at the time of surgery (11400-11471). When there is a prior biopsy showing malignancy, the excision can be coded as malignant at the time of surgery (11600-11646).
Coding excision of a cutaneous lesion pending pathology (eg, lesion of unspecified behavior) as malignant before pathology is available could result in incorrect coding if the lesion is found to be benign on histopathologic examination. Therefore, if the lesion is not clearly benign or malignant, coding and billing should be delayed until the pathology has been confirmed.
Note the final line in the first paragraph, “When there is a prior biopsy showing malignancy, the excision can be coded as malignant at the time of surgery (11600-11646).” In this case, you would report 11603 Excision, malignant lesion including margins, trunk, arms, or legs; excised diameter 2.1 to 3.0 cm, rather than the benign excision code 11403 Excision, benign lesion including margins, except skin tag (unless listed elsewhere), trunk, arms or legs; excised diameter 2.1 to 3.0 cm.

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John Verhovshek
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John Verhovshek, MA, CPC, is a contributing editor at AAPC. He has been covering medical coding and billing, healthcare policy, and the business of medicine since 1999. He is an alumnus of York College of Pennsylvania and Clemson University.

No Responses to “Q&A: Selecting a Follow-up Excision Code”

  1. Babu Kandoth says:

    I agree that it should be coded as malignant, as the Initial pathogist confirmed malignancy – at the second time the pathologist might not have the exact area/lesion, so he may not locate the malignancy. In this case a second opinion of both the specimens may sought from a panel/group of pathologist before starting the actual treatment and may change the codes also. Babu Kandoth

  2. Delly Parham, CPC says:

    If a biopsy at the first location (another office) reads malignant and the surgeon (dermatologist or mohs) did an excision, that excision would be billed with the malignant diagnosis code. The re-excision to clear margins would also be billed with the malignant diagnosis code regardless of the diagnosis code after the re-excision, provided that it was the same anatomical site.
    Hope this helps.

  3. MaraBeth Rheaume says:

    There is a moral issue with billing using the malignant diagnosis when the lesion is not malignant. This patient is now going to be followed with a malignant diagnosis when in fact they do not have a malignant skin lesion. This could lead to insurance issues of denials and pre-ex problems.

  4. Lauren says:

    But you use the dx for the reason why you did a procedure. Usually we bill, I work in a physicians office, prior to knowing the results of the path anyways. If a pap smear came up abnormal and the pt had to come back to do a repap, the insurance company wouldn’t pay for a preventive service again. I would have to use the reason why the pt came back..the abnormal pap.

  5. Caren Swartz says:

    @ MaraBeth there is no moral issue when the patient is already diagnosed with a malignancy. I agree that the proper way to code for this is to bill the malignant code for a re-excision.

  6. susan thomas parrott says:

    What if the results of the 1st biopsy come back with findings of atypical / abnormal cells, malignancy is not confirmed? I assume it would be billed with one of the biopsy codes in the benign lesion range, and if the patient had another biopsy done for confirmation, it too would be billed from the benign lesion codes?

  7. Shelley Williams says:

    If you have a recent path report that verifies the margins on the lesion are not clear- you can use the 11603.

  8. charles hamilton says:

    I am a retired dermatologist. I recently had a Sq Ca of one cm. excised from my arm via a simple elliptical 3 ” closure. I was billed for the removal of a malignancy and the closure billed as a repair. When I practiced ,closure was included in the removal however I was told using the two CPT codes was now standard. In 35 years of practice I never heard of such a thing.

  9. Melissa Loos, CPC CPMA says:

    Dr Hamilton,
    The simple repair is included in the excision, please have them fix it. 🙂

  10. Brad Ericson says:

    Hi Melissa,
    I’m glad to help, but I have a question: Have who fix it?

  11. Suzie Bartholomew says:

    I have two question on Mohs:
    If documentation does not support stage 1 and stage 2 Mohs.: 0.6 x 0.5 and 0.8 x 0.7.
    Do I bill two excisions and one repair? and how do I measure the size of excisions?