10-31-2025
Scenario: 2025-Diagnosis of simultaneous multiple tumors
- 2-12-2025 Shave biopsy skin right shoulder: Melanoma in situ
- 2-12-2025 Shave biopsy skin left upper back: Invasive Melanoma, Breslow thickness at least 0.8 mm
- Per Solid Tumor Rules Rule M4 Abstract multiple primaries when there are separate, non-contiguous melanomas with different lateralities
Question: Which case would be assigned to Seq 01?
- Melanoma In situ-right shoulder
- Invasive Melanoma-left upper back
Answer: Invasive Melanoma-left upper back- aka- The “Scariest tumor”-the one with the worst prognosis.
SEER/STORE manuals- Assign the lower sequence number to the primary with the worse prognosis when two primaries are diagnosed simultaneously
- Base the prognosis decision on the primary site, histology, and extent of disease for each of the primaries
- If there is no difference in prognosis, the sequence numbers may be assigned in any order
