J Korean Soc Endocrinol.  1996 Dec;11(4):401-408.

Surgical Findings of Benign Thyroid Nodule, Not Decreased After Thyroxine Suppression Therapy

• Byun DW
• Yoo MH
• Suh KI
• Lee HK
• Kim GB

Abstract

Background
Fine needle aspiration and biopsy(FNAB) has known the most accurate test(about 90%) in the preoperative evaluation of patients with a thyroid nodule. The false negative findings of thyroid cancer by FNAB are mainly due to the aspiration of cystic fluid in cystic degeneration of thyroid cancer and the ipossibility of differentiation between follicular adenoma and carcinoma by aspiration or FNAB because of the failure to evaluate the capsule invasion or angioinvasion of the tumor. Actually more than 80% of the nodules are found as benign nodules in aspiration or FNAB and the findings of follieular lesions are found about half of the samples tested, so limiting the cancer incidence in surgically resected samples up to 50% of the surgical resection. Sa reasonable guidelines to manage the benign nodules on aspiration or FNAB are needed which can select the maligna~nt nodules with false negative findings on aspiration or FNAB. We tried to evaluate whether the thyroxine suppression therapy can increase the malignancy rates on thyroidectomy, Methods: We treated the benign thyroid nodules in FNAB with thyroxine for 1 year and cornpared the nodule volume change before and after treatment (every 6 month) with ultrasonogram. We performed thyroidectomy on 1~7 thyroid nodules wbich showed less than 50% decrease of nodule volume after 1 year of thyroxine suppression therapy. Results: The results were as follows. 1) Of all 17 patients, surgical resection revealed malignant thyroid nodule(Group I) in 10 cases (58.82%, papillary cancer. 6 cases, follicular cancer: 4 cases) and benign thyroid nodule(Group II) in 7 cases(41.18%, follicular adenoma: 4 cases, adenomatous goiter: 3 cases). 2) Between group I and II, there was no significant differences in serum T, T and TSH levels before and after thyroxine suppression therapy. Also, there were no significant difference in TSH suppression % between group I and group II(5.60+5.39%, 14.64+11.48%, respectively). 3) Thyroid nodule volume decrease percent before and after thyroxi~ne therapy showed no significant difference between group I and group II (124.80+54.18% vs 159.42+79.82%, p>0.05). Conclusion: Our data suggested that the benign thyroid nodules on aspiration or FNAB which were not suppressed in volume after thyroixine therapy revealed more than 50% incidence of malignancy on surgical resection, so these nodules were highly reeommended to surgical exploration.

MeSH Terms

Adenoma
Biopsy, Fine-Needle
Goiter
Humans
Incidence
Thyroid Gland*
Thyroid Neoplasms
Thyroid Nodule*
Thyroidectomy
Thyroxine*
Ultrasonography
Thyroxine