EOD Primary Tumor
Notes
**Note 1:** Deep invasion (code 300) is defined as either invasion beyond the subcutaneous fat, or >6 mm deep (as measured from the granular layer of adjacent normal epidermis to the base of the tumor).
**Note 2:** In the case of multiple simultaneous tumors, code the tumor with the greatest extension.
**Note 3:** Skin ulceration does not alter the classification.
(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) Lydiatt, W.M., Patel, S.G., Shah, J.P., et al. **Staging Head and Neck Cancers**. In: Amin, M.B., Edge, S.B., Greene, F.L., et al. (Eds.) AJCC Cancer Staging Manual. 8th Ed. New York: Springer; 2017
(6) Califano, J.A., Lydiatt, W.M., Shah, J.P., et al. **Cutaneous Carcinoma of the Head and Neck**. In: Amin, M.B., Edge, S.B., Greene, F.L., et al. (Eds.) AJCC Cancer Staging Manual. 8th Ed. New York: Springer; 2017