Fig. 2

a. Pathological section (hematoxylin and eosin [HE] staining, × 100) showing an area with features of low-grade chondrosarcoma. b. The tumor in the left thyroid lobe infiltrating the remaining thyroid tissue (HE, × 40). c. A high-grade spindle cell sarcoma can be seen in some areas (HE, × 200). d. The spindle cells exhibit extensive pleomorphism, atypia, and a high mitotic rate (HE, × 400). e. The gray-white nodule in the right thyroid lobe comprises a prominently collagenous stroma and some bland spindle cells, which are infiltrating the surrounding thyroid tissue (HE, × 100). f. The brown nodule in the right thyroid lobe is a follicular adenoma (HE, × 40)