Lung cancer from a focal bulla into thin-walled adenocarcinoma with ground glass opacity - an observation for more than 10 years: A case report.

BACKGROUND: Thin-walled lung cancer manifests as a cystic lesion, mostly adenocarcinoma. It is often misdiagnosed as a benign lesion in clinical practice, thus delaying the diagnosis and surgical treatment. Its natural course is rarely recorded and observed; thus, the pathogenesis and diagnosis need to be clarified and improved. CASE SUMMARY: A 66-year-old man developed a mass in the upper lobe of the right lung and a small, thin-walled cavity in the lower lobe of the right lung in 2007. The right upper lobe mass was confirmed to be adenocarcinoma after surgery. The cavity diameter increased from 11 mm to 31 mm over 10 years, and a ground glass opacity lesion appeared around the bulla on computed tomography. A second operation confirmed that the lesion was lepidic predominant adenocarcinoma. Here we report a rare case of lung cancer developing from a focal bulla to a thin-walled adenocarcinoma for more than 10 years and confirm that the check-valve mechanism explains the pathogenesis. CONCLUSION: Solitary thin-walled lung adenocarcinoma is a rare tumor in terms of its clinical manifestations, pathogenesis, and disease progression. The check-valve mechanism can explain the cause of thin-walled lung cancer. Close follow-up and accurate imaging are necessary.