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SEER Inquiry System - Report
Produced: 06/04/2026 7:54 AM
Question 20061129
Inquiry Details
References:
2004 SEER Manual, 11. Rule 4, b.
Question:
Multiple Primaries (Pre-2007)--Head & Neck: How many primaries are abstracted if a patient has bilateral involvement of tonsils with the same histology (e.g. squamous cell carcinoma)? See Discussion.
Discussion:
Patient was initially found to have mass on right tonsil. Biopsy of right tonsil on June 16 showed invasive carcinoma, favor squamous cell. On July 17 patient underwent right neck dissection, radical resection of right tonsil tumor and left tonsillectomy. Right tonsil showed squamous cell carcinoma, poorly differentiated. Left tonsil showed squamous cell carcinoma, poorly differentiated. Microscopic report stated: Right tonsil: Invasion of deep peritonsillar tissue and skeletal muscle. Sections of left tonsil demonstrate squamous cell ca focally distributed in the tonsil, predominantly in situ, but with focal microscopic invasion. Path staged each tonsil specimen. Right tonsil was T2N1. Left tonsil was T1Nx.
Answer:
For tumors diagnosed prior to 2007:
Code as two primaries. Squamous cell carcinoma diagnosed in both left and right tonsils are multiple primaries unless one is stated to be metastatic from the other.
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:
2006
