[Analyses of multiple primary lung cancers; recent trend].

We studied multiple primary lung cancers (MPLCs) in 921 patients who had undergone operation for primary lung cancer since March 1979 in Mie University Hospital. There were 14 synchronous and 5 metachronous MPLCs. Combination of synchronous MPLCs were adenocarcinoma (ADC)/ADC in 7, squamous cell carcinoma (SCC)/SCC in 3, and ADC/adenosquamous cell carcinoma, ADC/small cell carcinoma, ADC/large cell carcinoma and multiple AAH in one. The incidence of synchronous MPLCs was 0.7% (6/815 pts) before May 1999 and 7.5% (8/106 pts) after June 1999 when HRCT was introduced for preoperative evaluation and postoperative follow-up. Six cases with multiple bronchioloalveolar carcinomas (BACs) have undergone operation for last 5 years. Most of them were roentgenographically occult and the operative outcome was good in spite of limited resection. In summary, we need new strategy of diagnosis and operative procedure for peripheral small adenocarcinoma, because multiple MPLCs of BAC are not rare.