Pathology/Lab Coding Alert

Question: The pathology report states, "right ovary with struma ovarii showing multifocal malignant transformation into the follicular variant of papillary thyroid carcinoma." What diagnosis code should I use?

Colorado Subscriber

Answer: Struma ovarii is a rare ovarian tumor defined by the presence of thyroid tissue comprising more than 50 percent of the overall mass. If you look in the ICD-9 Alphabetic Index, you will see you have 3 choices:

• struma ovarii: 220,
• struma ovarii, with malignancy: 183.0
• struma ovarii with carcinoid: 236.2.

Because the pathology report mentions malignancy, you should select 183.0 (Malignant neoplasm of ovary). Remember, you have a coding note that states, "Use additional code to identify any functional activity."

ICD-10: Beginning October 1, 2014, instead of ICD-9 183.0, you'll have 3 options under ICD-10: C56.1 (Malignant neoplasm of right ovary), C56.2 (Malignant neoplasm of left ovary), or C56.9 (Malignant neoplasm of unspecified ovary).