Fig. 2.

Cortical morphology of the SLNs on grayscale US. A Type I, SLN with thin hypoechoic cortex. The cortical thickness was less than 2.5 mm. B Type II, SLN with diffuse cortical thickening. The hypoechoic cortex is uniformly thicker than 3 mm. C Type III, SLN with focal eccentric cortical thickening (arrows). The cortex is thicker than 3 mm and the hilum is displaced. D Type IV, a round hypoechoic SLN with absent hilum. SLN sentinel lymph node