EOD Primary Tumor


**Note:** Extrathyroidal extension includes minor (microscopic) extension through the thyroid capsule which is identified only on microscopic examination (see code 200) to gross (macroscopic) extrathyroidal extension, which is documented in the operative report and involves major structures (see codes 300, 400, 600, and 700). * If the only information available is "extrathyroidal extension" and cannot determine whether it is microscopic or gross, code 200. * If the only information is "gross extrathyroidal extension" and the involvement of major structures cannot be determined, code 750.
Code Description SS2018 T
000 In situ, intraepithelial, noninvasive IS
100 Single invasive tumor confined/limited to thyroid Multiple foci confined/limited to thyroid Into thyroid capsule, but not beyond Confined/limited to thyroid, NOS Localized, NOS L
200 Microscopic extrathyroidal extension Extrathyroidal extension, NOS RE
300 Gross extrathyroidal extension invading - Pericapsular soft tissue/connective tissue - Strap muscle(s) + Omohyoid + Sternohyoid + Sternothyroid + Thyrohyoid RE
400 Moderately advanced disease WITH gross extrathyroidal extension invading - Cricoid cartilage - Esophagus - Larynx - Parathyroid - Recurrent laryngeal nerve - Sternocleidomastoid muscle - Subcutaneous soft tissues - Trachea - Vagus nerve Moderately advanced disease, NOS RE
600 Very advanced disease invading - Blood vessel(s) (major) + Carotid artery (encased) + Jugular vein + Thyroid artery or vein - Thyroid cartilage - Tumor described as "FIXED to adjacent tissues" Very advanced disease, NOS RE
700 Very advanced disease invading - Bone - Mediastinal tissues - Prevertebral fascia - Skeletal muscle, other than strap or sternocleidomastoid muscle Further contiguous extension D
750 Advanced disease, NOS Gross extrathyroidal extension, NOS RE
800 No evidence of primary tumor U
999 Unknown; extension not stated Primary tumor cannot be assessed Not documented in medical record Death Certificate Only U
(1) Fritz AG, Ries LAG (eds). **SEER Extent of Disease 1988: Codes and Coding Instructions (3rd Edition, 1998)**, National Cancer Institute, NIH Pub. No. 98-2313, Bethesda, MD, 1998 (2) Young JL Jr, Roffers SD, Ries LAG, Fritz AG, Hurlbut AA (eds.). **SEER Summary Staging Manual-2000: Codes and Coding Instructions**, National Cancer Institute, NIH Pub. No. 01-4969, Bethesda, MD, 2001. (3) Collaborative Stage Work Group of the American Joint Committee on Cancer. **Collaborative Stage Data Collection System User Documentation and Coding Instructions, version 02.05**. American Joint Committee on Cancer (Chicago, IL) (4) Gress, D.M., Edge, S.B., Gershenwald, J.E., et al. **Principles of Cancer Staging**. In: Amin, M.B., Edge, S.B., Greene, F.L., et al. (Eds.) AJCC Cancer Staging Manual. 8th Ed. New York: Springer; 2017 (5) Rosen, J.E., Lloyd, R.V., Perrier, N.D., et al. **Thyroid - Medullary**. In: Amin, M.B., Edge, S.B., Greene, F.L., et al. (Eds.) AJCC Cancer Staging Manual. 8th Ed. New York: Springer; 2017