#1: Solid Tumor Rules (2018)
#2: Multiple primaries
Source 1: 2018 Solid Tumor Rules
Notes: Lung, July 2019 Update
Solid Tumor Rules/Multiple Primaries--Lung: How many primaries are accessioned when a patient is diagnosed with right lower lobe invasive acinar adenocarcinoma (8551/3) in 2018 and treated with lobectomy, followed by a 2019 right middle lobe cancer (NOS, 8000/3) diagnosed as new stage 1 primary by cancer conference? See Discussion.
Lung Rule M14 appears to be the first rule that applies to this case and instructs the user to abstract a single primary. However, we were hoping for confirmation that a cancer (NOS) or malignancy (NOS) would not be a distinctly different histology that may qualify for Lung Rule M8. Currently, these histologic terms are not included in the Table 3 options or mentioned in the preceding notes.
Use M14 and code a single primary. Per our SME, carcinoma or cancer, NOS is not an acceptable diagnosis which is why 8000 and 8010 were not included in the tables or rules. We assume there was no tissue diagnosis for the 2019 diagnosis. We recommend searching for more information or better documentation on this case.