Expression of β-catenin and APC Protein in Thyroid Neoplasm and Its Implication

Objective: To investigate the expression of β catenin and protein APC in thyroid normal tissue, thyroid adenoma,thyroid carcinoma, and their implication. Methods: Immunohistochemical staining with S-P(S-ABC) method was conducted to determine the expression of β catenin and protein APC in thyroid normal tissue around thyroid adenoma (40 cases), thyroid adenoma (40 cases) and thyroid carcinoma (39 cases). Results: β catenin was normally positive in all 40 cases of normal thyroid tissue. Its abnormal expression was found in 23/40(57 5%) of adenoma and 39/39(100%) of carcinoma. Normal positive expression of APC protein was found in 40/40(100%) of normal tissue, 39/40(97.5%) of adenoma and 38/39(97.4%) of carcinoma. Conclusion: Expression of β catenin was uniformly positive in thyroid normal tissue. Its abnormal expression was found in thyroid adenoma and thyroid carcinoma. The rate of abnormal expression of β catenin in thyroid carcinoma is higher than that in thyroid adenoma. There was a significant difference of abnormal expression rate of β catenin between thyroid adenoma and thyroid carcinoma (P0.005). Obvious difference of expression of APC protein was not detected among thyroid normal tissue, thyroid adenoma and thyroid carcinoma (P0.05).