EOD Primary Tumor

Code	Description	SS2018 T
000	In situ, intraepithelial, noninvasive	IS
100	Localized, NOS - Confined to + Auditory bone(s) (incus, malleus, stapes) + Vestibulocochlear organ * Cochlea * Semicircular ducts (ampullae, saccule, utricle) * Septum * Tympanic membrane (ear drum)	L
200	Regional extension, NOS - Adjacent connective tissue + Auditory tube (Eustachian tube, pharyngotympanic tube) + Nerve(s) - Adjacent organ(s)/structure(s) + External auditory meatus (ear canal) + Internal carotid artery + Mastoid antrum + Nasopharynx + Temporal bone	RE
700	Meninges Further contiguous extension	D
800	No evidence of primary tumor	U
999	Unknown; extension not stated Primary tumor cannot be assessed Not documented in patient 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)