SCINTIGRAPHIC VARIETIES IN HASHIMOTOS-THYROIDITIS AND COMPARISON WITHULTRASONOGRAPHY

The scintigraphic findings in Hashimoto's thyroiditis are highly Varia ble and can mimic any thyroid abnormality. In this study, we compared the scintigraphic findings with ultrasonography in 48 patients with Ha shimoto's thyroiditis. Thyroid scintigrams revealed diffuse hyperplasi a in 12 patients, multinodular goiter in 20 patients and a solitary no dule in 16 patients (toxic adenoma, n = 1; hypoactive nodule, n = 4; h yperactive nodule with no suppression, n = 3; normoactive nodule, n = 8). Ultrasonography revealed diffuse hyperplasia in 19 patients, multi nodular goiter in 20 patients and a solitary nodule in 9 patients. The thyroid scan and ultrasonography revealed the same findings of diffus e hyperplasia in 12 patients and multinodular goiter in 20 patients. O f the 16 patients with a solitary nodule on scintigraphy, only 9 showe d the same finding on ultrasonography, with the other 7 showing diffus e hyperplasia. The difference in nodularity between thyroid scanning ( 74.9%) and sonography (60.4%) has been attributed to pseudonodularity in Hashimoto's thyroiditis. In conclusion, our results confirmed that Hashimoto's thyroiditis can mimic any thyroid abnormality, including d iffuse hyperplasia, nodular goiter and multinodular goiter on scintigr aphy. Therefore, scintigraphy, ultrasonography and serum thyroid hormo ne estimation alone may not be helpful for the final diagnosis of Hash imoto's disease. To eliminate unnecessary surgical intervention, all p atients should be evaluated by means of physical examination and thyro id autoantibodies, in addition to a thyroid scan, ultrasonography, ser um thyroid hormones and fine-needle aspiration biopsy when necessary.