Oncology & Hematology Coding Alert

Question: I have a patient with recurrent malignant phyllodes tumor of the right breast; according to the path report it is malignant and no longer benign. The physician strongly feels that the code should be D48.61. Based on the documentation and path, the tumor is indicated as a malignancy of the UOQ of right breast. Would C50.411 be more appropriate in this case?

AAPC Forum Participant

Answer: Based on the information you give, you could make a case for either of these codes — and possibly even a third.

The ICD-10-CM Alphabetic Index entry for tumor – phyllodes directs you to three probable code choices. The first two are

D48.61 (Neoplasm of uncertain behavior of right breast), which is what your provider suggests, and D24.1 (Benign neoplasm of right breast). However, the Index entry also directs you to see Neoplasm, breast, malignant if the tumor is, as you say, malignant. That would lead you to C50.411 (Malignant neoplasm of upper-outer quadrant of right female breast) as you suggest.

So, before you assign a definitive diagnosis, you should query your provider to clarify whether the tumor’s behavior is malignant, benign, or uncertain.