Lesions with a continuous margin (ie, the “A pattern”) in the EBUS image were noted in 34 patients (27.6%) with malignant lesions and 7 patients (6.9%) with benign lesions (p < 0.0001) [Table 2
]. The nonlinear, dotted, or mottled air bronchogram (ie, the “B pattern”) was found in the EBUS images of 113 patients (91.9%) with malignant lesions and 38 patients (37.6%) with benign lesions (p < 0.0001) [Table 2]. Heterogeneous echogenicity of the internal structure (ie, the “C pattern”) in the EBUS image was found in 80 patients (65%) with malignancy and in 10 patients (9.9%) with benign lesions (p < 0.0001) [Table 2]. The ORs for the presence of a continuous margin, the absence of linear-discrete air bronchogram, and heterogeneous echogenicity of the internal structure in predicting malignant lesions were 5.13 (95% CI, 2.16 to 12.10), 18.73 (95% CI, 8.75 to 40.14), and 16.93 (95% CI, 7.99 to 35.88), respectively. The existence of two EBUS patterns (A + B, A + C, or B + C) within the lesions was observed in 33 patients (26.8%), 11 patients (8.9%), and 75 patients (60.9%) patients with malignancy, respectively, and 6 patients (5.9%), 0 patients, and 7 patients (6.9%) with benign lesions, respectively. The OR for the presence of existence of any two of EBUS features in predicting malignant lesions was 45.27 (95% CI, 20.66 to 99.20). The coexistence of all three EBUS features was found in only 11 patients (8.9%) with malignancy, and was not found in any patient with benign lesions. By contrast, the absence of all three EBUS features within the lesion was found in only 4 patients (3.3%) with malignancy and in 60 patients (59.4%) with benign lesions. The absence of any one of the three EBUS features was noted in 2 of 71 patients with adenocarcinoma, in 1 of 38 patients with squamous cell carcinoma, and in 1 of 14 patients with small cell carcinoma. The presence of two EBUS features suggesting malignancy was found in 13 patients with benign lesions (13%) [4 patients with TB, 4 patients with anthracosis, 3 patients with lung fibrosis, 1 patient with organizing pneumonia, and 1 patient with granulomatous disease].