Oncology & Hematology Coding Alert

Question: A post-mastectomy patient with a diagnosis of invasive ductal carcinoma, coded to C50.911, went back to the operating room (OR) to have a nodule in the incision along the chest wall removed. The surgeon noted a chest wall resection of 3 cm x 6 cm. The office wants to code this as 21601 or 19301, but I don’t believe either is correct. How should I code this encounter?

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Answer: You are correct in dismissing 21601 (Excision of chest wall tumor including rib(s)) as the correct code to describe this procedure for the reason you mention: The op note did not indicate the removal of anything other than the lesion.

You would also not use 19301 (Mastectomy, partial (eg, lumpectomy, tylectomy, quadrantectomy, segmentectomy)) as the provider performed the procedure you describe post-mastectomy.

In this case, your best choice would likely be 11606 (Excision, malignant lesion including margins, trunk, arms, or legs; excised diameter over 4.0 cm) for three reasons:

• First, the provider chose C50.911 (Malignant neoplasm of unspecified site of right female breast), indicating they removed a malignant lesion based on the words “small local recurrence.”
• Second, 11606 describes the excision of a malignant lesion from the patient’s trunk, arms, or legs, which is the appropriate anatomic region for removal of a ductal carcinoma.
• Third, the excised lesion size was 3 cm x 6 cm. Since the largest diameter is 6 cm, and the note does not describe additional margins, the 6 cm exceeds the 4 cm diameter minimum described by the code, making 11606 the most appropriate code to use for this encounter.

Bruce Pegg, BA, MA, CPC, CFPC, Managing Editor, AAPC