Table 4.
Reported rate of malignancy in nodules with benign cytology according to US finding.
| Total number of nodules | Rate of malignancy (%) | Suspicious US features | |||
|---|---|---|---|---|---|
| Overall | Suspicious US | No suspicious US | |||
| Kwak et al. [9] | 1343 | 1.9 (26/1343) | 20.4 (19/93) | 0.6 (7/1250) | Marked hypoechogenicity, microlobulated or irregular margin, microcalcification, and taller than wider shape |
| Koike et al. [15] | 168 | 11.9 (20/168) | 47.1 (8/17) | 7.9 (12/151) | Ill-defined margin, irregular shape, solid echo structure, heterogeneous internal echogenicity, hypoechogenicity, presence of calcification, absence of halo, and invasion of adjacent organs |
| Lee et al. [16] | 560 | 1.1 (6/560) | 3.7 (4/108) | 0.4 (2/452) | Marked hypoechogenicity, microlobulated or irregular margin, microcalcification, and taller than wider shape |
| Maia et al. [17] | 35 | 28.6 (10/35) | 38.5 (5/13) | 22.7 (5/22) | Hypoechogenicity, microcalcification, border irregularity, and central flow by Doppler study |
| Choi et al. [18]∗ | 700 | 1.7 (12/700) | 4.7 (8/169) | 0.8 (4/531) | Marked hypoechogenicity, not well-defined margin, microcalcifications, and taller than wide shape |
Data in parentheses are numbers used to calculate percentages.
∗Multicenter study from 7 university-affiliated hospitals.