Fig. 4

a TTF-1 immunostaining of the thyroid. Positive TTF-1 staining was found in the nucleus of follicular cells in both (a) ectopic and (b) orthotopic thyroids. Positive cells in brown color were indicated by red arrow. TTF-1 expression was significantly higher in the ectopic thyroids than orthotopic thyroids (×400). The quantification data was shown in Table 4. b Thyroglobulin (TG) expression in thyroid. a ectopic thyroid. b orthotopic thyroid (×400). Positive staining (brown color) of thyroglobulin was found in the cytoplasm of thyroid follicular cells and extracellular areas in both ectopic and orthotopic thyroids. There were no significant differences between the ectopic and othortopic thyroid tissues. c Immunostaining of Ki-67 in the thyroid. a ectopic thyroid. b orthotopic thyroid. c Papillary thyroid carcinoma. (×400). In both the ectopic and orthotopic thyroids, the expression of Ki-67 was very low in thyroid follicular cells. Strong staining signals for Ki-67, as indicated by the arrow, was found in the papillary thyroid carcinoma. d Immunostaining of calcitonin in the thyroid. a ectopic thyroid. b orthotopic thyroid. c The medullary thyroid carcinoma. The ectopic thyroid and orthotopic thyroids were negative for calcitonin expression. The medullary thyroid carcinoma of thyroid showed a strongly positive staining for calcitonin