SEER Inquiry System - Question 20021082 Details

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Produced: 08/11/2026 7:55 AM

Question 20021082

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Inquiry Details

References:

SINQ 20021003

Question:

Multiple Primaries (Pre-2007)/Primary site/EOD-Extension--Head & Neck: How many primaries are represented by an invasive squamous cell carcinoma of the floor of mouth with in situ squamous cell carcinoma involvement of the frenulum?

Discussion:

Answer:

For tumors diagnosed prior to 2007:

Code the Primary Site field to C04.9 [floor of mouth]. Because the cancer did not INVADE into a neighboring site (through wall, through soft tissue), it just spread along the mucosa (in situ) to involve the frenulum, this is one primary.

For cases diagnosed 1998-2003, in situ extension via mucosal spread to the frenulum is ignored for purposes of coding EOD-Extension.

For tumors diagnosed 2007 or later, refer to the MP/H rules. If there are still questions about how this type of tumor should be coded, submit a new question to SINQ and include the difficulties you are encountering in applying the MP/H rules.

Cancer Site Category:

Head & Neck

Data Item Category:

N/A

Other Category:

Multiple primaries

Year:

2002