Clinical cytopathologic research on subclinical thyroid dysfunction.

Objective To investigate the etiopathogenisis and the clinical characteristics of subclinical hypothyroidism and subclinical hyperthyroidism by analyzing their thyroid fine needle aspiration cytologic(FNAC) results.Methods FNAC results during Septemper 1994 and December 2005 in Peking University First Hospital were reviewed in 90 patients with subclinical hypothyroidism and 48 ones with subclinical hyperthyroidism,and their serum levels of TGAb and TPOAb were measured.Results(1)The cytologic pathological results showed Hashimoto's thyroiditis was the most common in subclinical hypothyroidism(81.71%),while goiter and thyroid adenoma were less to be seen(12.19% and 3.66% respectively).In subclinical hyperthyroidism,Hashimoto's thyroiditis(41.86%),goiter(34.88%) and thyroid adenoma(13.95%)were all seen frequently.(2)The positive rates of TGAb and TPOAb in the former was significantly higher than those in the latter(P0.01).In subclinical hypothyroidism,the positive rates of TGAb and TPOAb in Hashimoto's thyroiditis were 83.08% and 84.62%,and those in subclinical hyperthyroidism were 77.78% and 55.56% respectively.(3)The pathological type of Hashimoto's thyroiditis and the cytopathological morphous of the same pathogeny had no obvious difference between subclinical hypothyroidism and subclinical hyperthyroidism.Conclusion Hashimoto's thyroiditis is the most common cause of subclinical hypothyroidism and plays an important role in the etiopathogenisis of subclinical hyperthyroidism.The positive rates of TGAb and TPOAb in subclinical hypothyroidism are significantly higher than those in subclinical hyperthyroidism.The different functions of subclinical thyroid disease can not be distinguished only by their cytologic pathology.