Different histological types of triple metachronous primary lung carcinomas in 1 patient: Case report.

INTRODUCTION: The documented incidence of multiple primary lung cancer has increased as a result of the widespread use of early detection tools. We report the successful surgical treatment of a case who had consecutive metachronous adenocarcinoma and squamous cell carcinoma of the lung after successful treatment for small cell carcinoma of the lung.A 73-year-old man underwent a routine health check-up. Computed tomography showed ground-glass opacity in the upper lobe of the right lung, which was diagnosed as small cell carcinoma. Twenty-nine months after concurrent chemoradiotherapy for the carcinoma, which was in complete remission, a nodule was detected in the apical segment of the right upper lobe. Histopathologically, the tumor was diagnosed as poorly differentiated adenocarcinoma. The second metachronous adenocarcinoma was completely removed by right upper lobectomy with lymph node dissection. Seventeen months later, the patient underwent left upper lobectomy with lymph node dissection and received 4 cycles of adjuvant chemotherapy for another moderately differentiated squamous cell carcinoma.

CONCLUSION: This case highlights the need for continuous screening for metachronous lung cancer following the successful treatment of primary lung cancer, even small cell carcinoma, to identify patients who could benefit from curative surgery.