Figure 1

(A) Calcified hypoechoic mass in the right thyroid lobe, measuring approximately 5.4 × 3.9 × 3.2 cm (35.3 mL); (B) A small amount of blood flow signal is seen inside the nodule."

Figure 2

(A) The mass in the right lobe of the thyroid gland showed heterogeneous hyperenhancement, with no enhancement in most of the central area; (B) CEUS revealed no enhancement in most areas of the mass. There was irregular ring with 0.8 cm thickness and other enhancement in the periphery, and the lesion reduction rate was 58%; (C) CEUS revealed no enhancement inside the mass, irregular hyperenhancement in the peripheral ring, significantly smaller peripheral irregular hyperenhancement in the active area (0.29 cm at the thickest site), and a lesion reduction rate of 77%."

Figure 3

With hematoxylin and eosin staining specimen of the thyroid lesion (A. × 40 magnification), pathological results indicated poorly differentiated squamous cell carcinoma. Immunohistochemical staining of primary squamous cell carcinoma of the thyroid (× 40 magnification) showed negative for TTF-1 (B) and PAX-8 (C)while the immunohistochemical staining for Ki-67 was positive (D)."

Figure 4

After three cycles of chemotherapy, the overall volume of the mass, the volume of the necrotic area, and the volume of the residual active area gradually decreased, showing a decreasing trend as a whole."