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SEER Inquiry System - Report
Produced: 06/27/2026 3:52 AM
Question 20150009
Inquiry Details
References:
2007 MP/H Rules
Question:
Multiple Primaries/Behavior--Lung: When a patient has an invasive lung primary, how do in situ tumors of the lung affect the determination of multiple primaries? See discussion.
Discussion:
How many primaries should be reported when a 12/19/14 RUL lung wedge resection shows: 2.0 cm invasive adenocarcinoma (8140/3) and an additional RUL wedge resection during the same procedure shows: multifocal adenocarcinoma in situ (bronchioloalveolar carcinoma), non-mucinous type (8252/2) size: 1 mm – 2 mm; followed by a 2/12/15 left upper lobectomy also showing Adenocarcinoma, invasive at several foci, with a prominent bronchioloalveolar (in situ) component….tumor focality: multifocal (10 cm mass, 6 cm mass and numerous smaller foci)?
Answer:
Most often when the invasive tumor and the in situ component are in the same lung and are the same histology, rule M12 (example 3) applies and this is a single primary. If the first wedge resection included part of the tumor and the in situ was not separate from the tumor, it is a single primary. We suspect that the margins were positive on the first wedge specimen which prompted the second wedge resection where the in situ was found. In addition, terminology for lung malignancies is undergoing change: what was called BAC (invasive) is now called adenocarcinoma in situ.
