Figure 3: Pathological findings (original magnification 400). In the surrounding thyroid tissue, the color tone of the follicle colloid was a light bluish color ((a), hematoxylin and eosin). The thyroid tumor consisted of mainly compact collections of small follicles that lacked colloid ((b), hematoxylin and eosin). Strong cytoplasmic Tg immunostaining was observed in both the surrounding thyroid tissue (c) and the hyperplastic nodule (d), although its appearance in the follicle lumen was deficient. NIS immunostaining was observed in the surrounding thyroid tissue (e). On the other hand, NIS immunostaining was hardly detected in the hyperplastic nodule (f).