Fig. 5From: Collision tumor of a papillary and follicular thyroid carcinoma: a case reporta The image of invasion of PTC to the inferior pharyngeal constrictor muscle (× 20, hematoxylin–eosin). Arrowhead: partially resected cricoid cartilage. Arrows: surgical ablation margin which was judged to be positive. b The image of capsular invasion of FTC (× 20, hematoxylin–eosin). Arrows: the tumor capsuleBack to article page