Question: The op note states that a patient undergoing a lumpectomy has a history of DCIS. How should I code the diagnosis? Texas Subscriber Answer: Ideally, you would wait for the pathology report and code the final diagnosis for the lumpectomy. Without a final diagnosis, you’ll have to code the “ordering diagnosis” or the reason for the test. You don’t mention any other signs or symptoms from the op report, such as a perceived “lump” or an abnormal mammogram. With the information you have, you’re left with coding the personal history of ductal carcinoma in situ (DCIS). The appropriate ICD-10 code would be Z86.000 (Personal history of in-situ neoplasm of breast). Don’t confuse the personal history code with codes for the condition, which are: