An official website of the United States government
Home
SEER Inquiry System - Report
Produced: 10/12/2025 7:22 PM
Question 20031145
Inquiry Details
References:
SEER EOD-88, 3rd Ed, 36. January 1998
Question:
EOD-Extension--Head & Neck: Is this field coded 10 [Invasive tumor confined to one of the following subsites: interior wall, one lateral wall, posterior wall] or 30 [Localized, NOS] for tonsillar primary when there is no mention of involvement of surrounding structures? See Description.
Discussion:
Site is stated to be "left tonsil" and was coded to site C099. "The lesion is admixed in tonsillar tissue." No surrounding structures are stated to be involved. Is it logical to assume that since code C099 includes the palantine tonsils and the palatine tonsils are on the lateral wall and since no other areas are stated to be involved that extension code 10 [confined to one lateral wall] would be more appropriate than code 30 [localized NOS]?
Answer:
For cases diagnosed 1998-2003: Code EOD-extension for the case example to 10 [Invasive tumor confined to one of the following subsites: anterior wall, one lateral wall, posterior wall]. The tonsil lies in a pocket on the wall (tonsillar fossa), so you know it is confined to the wall.
Cancer Site Category:
Head & Neck
Data Item Category:
N/A
Other Category:
N/A
Year:
2003
