镜下，正常甲状腺由滤泡构成。这些滤泡内衬上皮，充满胶质。甲状腺滤泡大小略有差别。间质不明显，其内可见C细胞。
正常甲状腺:大体 低倍 高倍 免疫过氧化物酶染色
Normal thyroid seen microscopically consists of follicles lined by a an epithelium and filled with colloid. The follicles vary somewhat in size. The interstitium, which may contain "C" cells, is not prominent.
