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SEER Inquiry System - Report
Produced: 01/09/2026 2:47 PM
Question 20091092
Inquiry Details
References:
2007 SEER Manual, C-496. Appendix C
Question:
MP/H Rules/Histology--Lung: How should Diagnosis Date, Diagnostic Confirmation and Histology be coded for the LEFT lung mass in the following case?
PET shows a 3 cm mass in the left lung and a 2.9 cm mass in the right lung. No reportable terminology in PET. The right mass is biopsied and shows adenocarcinoma. The left mass is not biopsied. Based on rule M6, this should be reported as two primaries. No additional information in medical record. Patient expired.
Discussion:
Answer:
For cases diagnosed 2007 or later:
For date of diagnosis, use the date of the PET scan for both primaries. For the left tumor, assign diagnostic confirmation code 8 [Clinical diagnosis only] and assign histology code 8000/3 [malignant neoplasm].
The left lung mass is reported as a separate primary because there is one tumor in each lung. According to Rule M6, when there is one tumor in the left lung and one tumor in the right lung, each tumor is a separate primary. Tumor and mass are equivalent terms for purposes of the multiple primary rules.
