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a prophylactic neck dissection is controversial (see discussion later in this chapter’s Key Question). Preoperative ultrasonography is important in determining the pres- ence of macroscopic lymph node metastases, which will be clinically evident in ap- proximately 20% to 31% of cases and, if present, may potentially alter the surgical approach (Fig. 2-1). 65–69 Identification of involved central compartment (level VI) lymph nodes by ultrasonography may be limited because of the overlying thyroid, depth from the skin, or acoustic shadowing from the manubrium and clavicles. 70–73

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FIGURE 2-1  Ultrasound images of metastatic lymph nodes (arrows) in papillary thyroid cancer in (A) central neck with cystic appearance and round shape and (B) lateral compartment with hy- perechoic tissue that resembles thyroid with microcalcifications; T: Trachea, C: Carotid; IJ: Internal jugular vein.