[Incidental Detection of Adenosquamous Carcinoma on Lobectomy for Posttreatment Local Recurrence of Small Cell Lung...

A 70-year-old man with two solid pulmonary nodules in the right upper lobe and an enlarged mediastinal lymph node underwent diagnostic thoracoscopic surgery. He was diagnosed with mixed small cell carcinoma cT1cN2M0 StageⅢA and squamous cell carcinoma cT1cN0M0 StageⅠA3, received concurrent chemoradiotherapy, and achieved complete response. However, two years after the initial treatment, a mass suggestive of local recurrence was observed along the staple line of the right upper lobe. He underwent right upper lobectomy for diagnosis and treatment. The diagnosis was recurrence of small cell lung cancer, but incidentally, concurrent adenosquamous cell carcinoma was identified. After treatment for small cell lung cancer, attention should be paid to the occurrence of secondary cancers.