Divide the nodal diameter groups (n=165) D (mm) benign (%) malig (%) Sum (%) p 8 - <10 9 (100, 0) 0 (0, 0) 9 (5, 5) 2 = 28, 33 p <0, 0001 10 - <15 18 (78, 3) 5 (21, 7) 23 (13, 9) 15 - <20 26 (63, 4) 15 (36, 6) 41 (24, 8) 20 - <25 27 (42, 9) 36 (57, 1) 63 (38, 2) 25 - <30 6 (20, 7) 23 (79, 3) 29 (17, 5) Tổng 85 (51, 5) 80 (48, 5) 165 (100, 0) 12 Conclusion: The nodules have average diameter of 20 - ≤25 mm are most (38, 2%).