Ob-Gyn Coding Alert

Question: I have a path report stating "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, and
• struma ovarii with carcinoid: 236.2.

As this path report talks about malignancy, you should be reporting 183.0 (Malignant neoplasm of ovary). Remember, you have a coding note there stating "Use additional code to identify any functional activity."

ICD-10: After October 1, 2013 hits, this code will expand into 3 options: C56.1 (Malignant neoplasm of right ovary), C56.2 (Malignant neoplasm of left ovary), and C56.9 (Malignant neoplasm of unspecified ovary).