Abstract
Objectives : The serum levels of thyroid stimulating hormone (TSH) were investigated in relation to thyroid malignancy, in order to lower the false-negative rate in thyroid fine-needle aspiration cytology.
Study Design : The preoperative serum TSH levels of 276 thyroid patients were tested. All patients had fine-needle aspiration cytology, then underwent surgical treatments, the histological diagnoses were confirmed, and the significance of the TSH levels was statistically investigated.
Results : TSH levels were significantly different between benign and malignant thyroid diseases (p=0.011, t test). Thyroid cancers were more frequent in those with TSH levels of more than 1.8μIU/ml compared to those with TSH levels less than 1.8μIU/ml (p<0.001, χ2 test). The odds ratio was 5.06. Furthermore, even in 170 patients with a negative diagnosis based on the cytology, thyroid cancers were more frequent also in those with TSH levels of more than 1.8μIU/ml (p=0.020, χ2 test), and the odds ratio was 3.25. By combining the serum TSH test for 170 patients with negative cytology diagnosis, false-negative cases were reduced to 12 cases from 19 cases.
Conclusion : Even if the result of cytology examinations are negative, patients with TSH levels of more than 1.8μIU/ml have a higher risk of malignancy, and should be further examined or surgically treated. This may result in fewer false-negative cases in thyroid cytology.
