Fine needle aspiration cytology, sonography and radionuclide scanning in solitary thyroid nodule.

One hundred and ninety three consecutive patients with solitary thyroid nodule (STN), with a mean age of 36.0 +/- 12.8 years and male to female ratio of 5.6:1, were studied. Ninety five percent of patients came from iodine deficient regions. Seventy two percent presented for local neck swelling, 12.4% for hyperthyroid state and in 7.7% STN was discovered incidentally. Scintigraphically, 77.7% of nodules were cold, 12.4% hot and 8.5% warm. Sonographic evaluation did not reveal any characteristic echotexture diagnostic of malignancy, but detected clinically nonpalpable accessory nodules in 20.6% of patients. Fine needle aspiration cytology was positive for malignancy in 6.2% of patients. Features of follicular and Hurthle cell neoplasm were seen in 12.9% of aspirates. Eighty eight (45.6%) STN were resected surgically. Histologically, there was one false positive and one false negative aspirate and a case of parathyroid adenoma on aspiration proved to be parathyroid carcinoma on histology.