Table 2.

Ultrasonographic features of thyroid metastasis from clear cell renal cell carcinoma reported in previous studies.

Study	Year	Cases reported, n	Ultrasonographic features
Vandemergel et al. (4)	2021	1	Single lesion, solid, hypoechoic, irregular shape, lobulated, without calcification, and with rich blood flow
Tian et al. (5)	2020	1	Multiple lesions, hypoechoic, solid-cystic, unclear boundary, with calcification, and with relatively rich blood flow
Al Abdrabalnabi et al. (6)	2019	1	Single lesion, solid-cystic, unclear boundary, without calcification
Song et al. (7)	2017	9	Single lesion (3/9), multiple lesions (6/9), solid (9/9), hypoechoic (9/9), clear boundary (8/9), with calcification (0/9), and with rich blood flow (9/9)
Gheorghiu et al. (8)	2016	1	Single lesion, mixed echoic, solid-cystic, clear boundary, without calcification and with rich blood flow in the solid region
Cilengir et al. (9)	2016	1	Single lesion, solid, hypoechoic, with clear boundary, irregular shape, lobulated, with microcalcification, and with rich blood flow
Kobayashi et al. (10)	2015	10	Single lesion (8/10), multiple lesions (2/10), solid (10/10), hypoechoic (10/10), clear boundary (10/10), irregular shape (9/10), without calcification (10/10), and with rich blood flow (10/10)
Andrioli et al. (11)	2014	1	Single lesion, solid, hypoechoic, without calcification, posterior irregular margins, and with rich blood flow