Usefulness of ultrasonography in the management of nodular thyroid disease.

BACKGROUND: Fine-needle aspiration biopsy is the standard diagnostic test for evaluating possible malignancy in a thyroid nodule. OBJECTIVE: To evaluate the role of routine ultrasonography in the management of nodular thyroid disease. DESIGN: Retrospective chart review. SETTING: Multidisciplinary thyroid nodule clinic (endocrinology and radiology). PATIENTS: Patients with suspected nodular thyroid disease or suspected recurrent thyroid cancer referred between October 1995 and March 1997. All patients had thyroid ultrasonography and ultrasonography-guided fine-needle aspiration biopsy of nodules at least 1 cm in maximum diameter. MEASUREMENTS: Medical records, ultrasonography findings, cytology reports, and histologic reports were reviewed. Ultrasonography findings were compared with the referring physician's findings on physical examination. RESULTS: 223 patients were seen in the clinic. A total of 209 fine-needle aspiration biopsies were performed on 156 patients. Among 50 of 114 patients referred for a solitary nodule, ultrasonography detected additional nonpalpable nodules at least 1 cm in diameter in 27 and determined that no nodules required aspiration in 23. Of 59 patients referred for a diffuse goiter or a multinodular gland, ultrasonography detected discrete nodules at least 1 cm in diameter that required aspiration in 39 and determined that aspiration was unnecessary in 20. CONCLUSIONS: Ultrasonography altered the clinical management for 63% of the patients (109 of 173) referred to the thyroid nodule clinic after abnormal results on thyroid physical examination.

The effect of droloxifene and estrogen on thyroid function in postmenopausal women.

Estrogen is known to increase serum T4-binding globulin (TBG) concentrations, thereby increasing serum total T4 concentrations. Serum free T4 concentrations, however, remain normal. Tamoxifen, a selective estrogen receptor modifier (SERM), also raises serum TBG concentrations, but whether newer SERMs with less stimulatory action on the endometrium do so is not known. We, therefore, compared the effect of droloxifene, a SERM, and conjugated equine estrogen on pituitary-thyroid function in normal postmenopausal women. Ten women were treated for 6 weeks with conjugated estrogen (Premarin), 0.625 mg/day, and droloxifene, 60 mg/day, in a double-blind crossover study with an intervening 4-week no-treatment period. We measured serum T4, T3, TBG, free T4 index, and TSH at baseline and at the end of each 6-week period. The baseline values were compared with the 6-week values using paired t tests. The mean (+/- SD) serum TBG concentrations increased significantly during both treatment periods (baseline, 1.5+/-0.4 mg/dL; conjugated estrogens, 2.7+/-0.6 mg/dL; droloxifene, 2.1+/-0.6 mg/dL; P < 0.001 and P = 0.001, respectively). There were no significant changes in the serum free T4 index. Serum T4 and T3 concentrations increased during both treatment periods, however, the increase was significant only for T4 during the conjugated estrogen treatment period. The serum TSH concentrations increased significantly during both treatment periods (18% during conjugated estrogen and 11% during droloxifene), and the values remained within the normal range in all women. Administration of both conjugated estrogen and droloxifene for 6 weeks increases serum TSH and TBG concentrations, but does not alter free T4 index values in postmenopausal women.

Subclinical thyrotoxicosis.

Subclinical thyrotoxicosis is defined as low serum thyrotropin (TSH) and normal serum thyroid hormone concentrations. It must be distinguished from nonthyroidal illness and secondary hypothyroidism. The most common causes are excessive thyroid hormone therapy, autonomously functioning thyroid adenoma, multinodular goiter, and Graves' disease, but many patients have no evident thyroid disease. A few patients have minor symptoms and signs of hyperthyroidism. The likelihood of progression to overt thyrotoxicosis is low, and many patients have normal serum TSH concentrations weeks or months later. Treatment should be based on consideration of the cause of the subclinical thyrotoxicosis, and whether the patient has any clinical manifestations of thyroid hormone excess or underlying problems likely to be aggravated by small increases in thyroid secretion.

Thyroiditis after pregnancy loss.

We present a case series evaluating the development and characteristics of thyroiditis following pregnancy loss. Five women were followed prospectively with measurement of thyroid function and antithyroid antibodies after pregnancy loss. Serum TSH concentrations were measured by immunoradiometric assay and antithyroid antibodies by RIA and hemagglutination techniques. All women had normal serum TSH concentrations before conception or at the time of pregnancy loss, and all but one had positive antithyroid antibodies. Pregnancy loss occurred between 5-20 weeks gestation because of ectopic pregnancy or either spontaneous or elective abortion. Two women had subclinical hypothyroidism with peak serum TSH values of 8.7 mU/L and 5.4 mU/L at 2 and 7 months after pregnancy loss, respectively. Three women had clinical hyperthyroidism with serum TSH values < or = 0.2 mU/L diagnosed between 3-11 months after pregnancy loss followed subsequently by a hypothyroid phase. Painless thyroiditis within 1 yr of pregnancy loss in these women suggests that the immunological changes of a short-term gestation may be sufficient to lead to thyroiditis.