Imaging-Cytology Correlation of Thyroid Nodules with Initially Benign Cytology

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.