Thyroid nodules are common in medical practice. To establish the predictive values of diagnostic tests we studied prospectively the results obtained from physical examination, aspiration cytology, scintigraphy, ultra-sonography and pre-operative serum thyroglobulin in 110 patients operated and compared them with the results obtained from surgical pathology specimens. We found 124 lesions in the 110 patients: 106 (85%) benign and 18 (15%) malignant. The benign were 90 simple goiters (73%), 8 follicular adenomas (6%), 4 thyroglossal cysts (3%) and 4 other rare lesions; the malignant were 16 (13%) primary thyroid carcinomas (9 papillary, 3 follicular, 3 undifferentiated and 1 medullary) and 2 secondary thyroid carcinomas. Aspiration cytology presented the best results (sensitivity: 94%, specificity: 97%), compared with scintigraphy (sensitivity: 89%, specificity: 21%), ultra-sonography (sensitivities from 60 to 100%, specificities from 25 to 69%) and pre-operative serum thyroglobulin (very low sensitivity and high specificity). Few clinical signs and symptoms also presented high specifity, but low sensitivity, as hoarseness, dysphagia, new lesion, cervical adenomegaly and previous local irradiation. We conclude that aspiration cytology is the best available method to diagnose thyroid nodules.
Thyroid nodule; Fine-needle aspiration cytology; Ultra-sonography; Thyroglobulin; Scintigraphy
