Objective  ATo investigate whether differentiated thyroid carcinoma (DTC) is a hormone-dependent neoplasm, and analyze the relationship between the expressions of ER/PR in DTC with tumor size, histology types, lymph node metastasis, and gender, age.

  Methods  To detect the expression of estrogen receptor(ER)/Progesterone Receptors(PR) in normal thyroid tissue, thyroid benign tumor, and DTC by using the immunohistochemical staining technique (SP method).

  Results  There was no expression of ER/PR in most cases of normal thyroid tissue and benign tumor. The positive rates of ER/PR were 19.3% (10/52) /30.8% (16/52) in DTC. The positive rate of ER/PR was significantly higher in DTC than in the normal thyroid tissue, nodular goiter, and follicular adenoma; there was a significant difference among them (P < 0.01). The positive rate of ER/PR in cases of tumor with diameter of more than 1 cm was significantly higher than those of tumor with diameter of not more than 1 cm; there was a significant difference between them (P < 0.01). However, the expression positive rate of ER/PR in DTC was related to gender, age, histology types, and lymph node metastasis.

  Conclusion  The positive rate of ER/PR in DTC was higher than those in normal thyroid tissue, nodular goiter, and follicular adenoma; there was a statistical significance among them(P < 0.01). The positive rate of ER/PR in cases of tumor with diameter of more than 1 cm was significantly higher than those of tumor with diameter of not more than 1 cm. The result suggested that DTC may be a kind of estrogen/progesterone-dependent neoplasm.