Podiatry Coding & Billing Alert

Question: My podiatrist saw a patient who fractured his right foot. The patient was diagnosed with left upper lobe carcinoma five years ago, and then several months ago, he was diagnosed with metastatic bone cancer (from the lung). The patient’s foot fracture was a result of the metastatic cancer. The patient’s lung cancer has already been treated with radiation, and the patient no longer had any evidence of an existing primary malignancy. Is this a pathologic or traumatic fracture? And what diagnosis codes should I report?

Florida Subscriber

Answer: As this fracture is pathologic (caused by a condition that weakens the bone) rather than traumatic (caused by a physical stress on the bone), diagnosis coding for this scenario will begin with a code from M84.- (Disorder of continuity of bone) (traumatic fractures, as the Excludes2 note for M84.- tells you, should be coded by fracture site).

Under M84.-, you then have the following choices:

• M84.3 (Stress fracture)
• M84.4 (Pathological fracture, not elsewhere classified)
• M84.5 (Pathological fracture in neoplastic disease)
• M84.6 (Pathological fracture in other disease)
• M84.8 (Other disorders of continuity of bone)
• M84.9 (Disorder of continuity of bone, unspecified)

Given that the patient’s lung cancer has metastasized in the bone, M84.5- would be correct for this encounter. You’ll then add 5th and 6th characters to specify the anatomic site for the fracture — in this case, 5th character 7 for the ankle and foot and 6th character 4 for the right foot. You’ll also need to add a 7th character to specify the encounter level; assuming this is the first, or initial, patient visit to your podiatrist, that character will be A, leading to the primary diagnosis code of M84.574A (Pathological fracture in neoplastic disease, right foot, initial encounter for fracture) for the encounter.

But ICD-10-CM coding in this scenario doesn’t end there. Under M84.5-, you’ll find a Code also instruction to code the underlying neoplasm that caused the fracture. In this case, you’ll code the metastatic bone cancer with C79.51 (Secondary malignant neoplasm of bone). And, as the patient’s cancer was treated with radiation therapy and there is no evidence of the primary malignancy, you’ll also need to record the patient’s current cancer status with two personal history codes: Z85.118 (Personal history of other malignant neoplasm of bronchus and lung) and Z92.3 (Personal history of irradiation).