The two most important purposes of fiberoptic bronchoscopy in lung cancer patients are obtaining tissue diagnosis and staging. The direct sign of lung cancer on FOB includes visible tumor, with smooth or nodular surface, with or without necrosis and infiltration. Variant cell typed of lung cancer have their characteristic biological behaviors respectively. For example, squamous cell carcinoma grows slowly, invades locally and has easy necrosis resulting in cavitation whereas adenocarcinoma shows early metastasis, small cell carcinoma shows rapid growth and higher early metastasis rate. Based on this, it could be hypothesized that each cell type may have characteristic bronchoscopic fading.

To answer this question, we reviewed 166 cases which were diagnosed as primary lung cancer and had bronchoscopically visible specific cancerous lesions.

The results were as follows. 1) Squamous cell carcinoma accounted for 66 cases(62.2%), adenocarcinoma 15 cases(14.2%), large cell carcinoma 3 cases(2.8%). 2) The endobronchial tumor lesion was arbitrarily classified into 5 types according to gross characteristics. Type 4, multilobulating mass with necrosis, accounted for 24.5%, type B, multilobulating mass without necrosis, 25.5%, type C, round beefy mass, 9.4%, type D, infiltration with mucosal irregularity, 6.6%, and type E, infiltration without mucosal irregularity, 34%. 3) The analysis of correlation between endobronchial tumor pattern and specific cell type revealed that squamous cell carcinoma had relation with the morphologic type B and small cell carcinoma had relation with the morphologic type E, but adenocarcinoma had no preponderance in morphologic type. The gross appearance had influence on the diagnostic yields of biopsies and the diagnostic yields of lobulating mass types(type 4, B) were higher than those of other types.

From the above observations, it could be concluded that squamous cell carcinoma and small cell carcinoma have relations with specific types of bronchoscopic morphology, but not the case in adenocarcinoma.