[Analysis of small lung nodules diagnosed by open lung or thoracoscopic biopsy]

We examined clinicopathologic findings in 86 cases with peripheral lung nodules less than 30 mm in size diagnosed by open lung or video-assisted thoracoscopic surgery (VATS) biopsy. Biopsies were conducted because of the new appearance or enlargement of nodules as evidenced in a comparison with retrospective chest films in 47 patients, X-ray findings of malignancy suspicion without retrospective films in 13, enlargement of nodules after the administration of antituberculosis agents in 9, and a past history of malignancy in 17. Mean tumor size was 18.1 mm in primary lung cancer (n = 29), 16.2 mm in metastatic lung cancer (n = 13), 16.3 mm in tuberculosis (n = 18), 15.3 mm in nonspecific inflammation (n = 12), 16.7 mm in benign lung tumors (n = 7), 7.5 mm in intrapulmonary lymph node (n = 2), and 19.4 mm in others (n = 5). Among primary lung cancers with a clear N-factor, the percentage of T1N0M0 cancers was up to 72%. No significant difference was observed in either of the reasons for these biopsies and the size of nodules among diseases. To detect early lung cancer and increase the rate of cure, small pulmonary nodules that could be hardly diagnosed using bronchoscopic or needle aspiration biopsy should be diagnosed positively using VATS biopsy.