An official website of the United States government
Home
SEER Inquiry System - Report
Produced: 01/17/2026 2:28 AM
Question 20031079
Inquiry Details
References:
SEER Program Code Man, 3rd Ed, 92
Question:
Discussion:
We have a case of metastatic keratinizing squamous cell ca. The work-up shows small densities in the lung that may represent inflammatory or chronic changes. No other imaging that shows origin. Physical exam states 2 months of left axillary mass. H/O SCCA of the skin involving chest wall.
Path reads: Metastatic w/d keratinizing SCCA. This lesion almost undoubtedly represents mets. The most likely site of origin is lung followed by esophageal primary or head & neck. The final discharge states, "Metastatic SCCA to Left Axilla".
Answer:
Code the primary site according to the physicians' opinion, especially the treatment decision. If the physician treats the patient for a lung primary, code primary site as lung. If the primary site cannot be determined, code C80.9.
According to the pathologist, the most likely primary site for the example above is lung. The final discharge diagnosis does not reflect the pathologist's opinion, and does not contradict it either. If there is no conflicting medical opinion, code primary site to C34.9 [lung].
