Value of Thyroid Imaging Reporting and Data System in Initial Bethesda Category III Thyroid Nodules
Table 3
Ultrasonographic characteristics and rates of malignancy of the 188 nodules with initial Bethesda system III cytology.
US features
Total (n = 188)
Benign (n = 82)
Malignant (n = 106)
Chi-square value
value
Composition
4.81
0.028
Solid
180
75
105
Mixed
8
7
1
Echogenicity
86.97
<0.001
Hypoechoic
95
71
24
Isoechoic
2
2
0
Hyperechoic
4
3
1
Marked hypoechoic
87
6
81
Margin
8.74
0.003
Ill-defined
68
20
48
Well-defined
120
62
58
Calcifications
9.35
0.009
Microcalcification
51
14
37
Macrocalcification
43
18
25
Absent
93
50
43
Shape
25.43
<0.001
Taller than wide
56
15
41
Irregular
31
6
25
Ovoid to round
101
61
40
TI-RADS#
21.69
<0.001
Category 4b
35
25
10
Category 4c
128
43
85
Category 5
12
1
11
No cyst nodules on Bethesda system III cytology. #Each of the 13 nodules classified as TI-RADS category 4a was benign. US, ultrasound; TI-RADS, Thyroid Imaging Reporting and Data System.
