Combined small cell lung cancer originated from small pure ground-glass nodule—Long-term observation after computed tomography screening

Combined small cell lung cancer is relatively rare. We report a case of combined small cell lung carcinoma that was suspected to originate from a small pure ground-glass nodule; the tumor was detected during a computed tomography (CT) health screening and observed periodically over 4 years. Surgical resection was performed; histology showed features of both adenocarcinoma and small cell carcinoma. The tumor histogenesis was interesting. Our result suggested that if a solid component appeared as a pure ground-glass nodule, clinicians should pay attention to both the CT -value and the doubling time. Not miss the timing of surgical resection considering of possibility of combined small cell lung carcinoma.