The Clinical Feature of Patients with Thyroid Nodule Combined with Hashimoto's Thyroiditis

ABSTRACT

PURPOSE: This study investigated the clinical features of patients with thyroid nodule combined with Hashimoto's thyroiditis, and the latter was incidentally detected after surgery. METHODS: The authors retrospectively evaluated 43 patients who were diagnosed with Hashimoto's thyroiditis after thyroidectomy between January 2001 and December 2006 at Chosun University Hospital. RESULTS: All patients underwent ultrasonography for the diagnosis of thyroid nodules. Ultrasonography revealed 16 calcified nodules with ill-defined margins, and these nodules were suspicious for malignancy. On performing preoperative fine needle aspiration, 37 cases were suspicious for malignancy or they were diagnosed as malignancies. All the thyroid nodules were taken for frozen section examination during surgery. On the frozen sections, 19 cases that were suspicious for malignant tumors underwent near total or total thyroidectomy along with central lymph node dissection, whereas 24 cases that were diagnosed as benign tumors underwent near total thyroidectomy or thyroid lobectomy. Based on the histopathological findings, 21 cases were diagnosed as Hashimoto's thyroiditis associated with papillary cancer; the nodules of these 21 cases were on average 0.75 cm, Twenty two cases were diagnosed as Hashimoto's thyroiditis associated with benign tumors, and the nodules of these cases measured on average 1.6 cm. CONCLUSION: Hashimoto's thyroiditis may present with a variety of clinical features, atypical ultrasonographic findings and a high false positive rate on fine needle aspiration. For the cases where Hashimoto's thyroiditis is suspected before surgery, serum antibody tests, ultrasonography and fine needle aspiration should be performed for making the accurate diagnosis of Hashimoto's thyroiditis. For the cases of suspicious malignant tumors, frozen section examination should be performed during surgery to decide on the correct operative procedure.