Needle aspiration of 310 thyroid lesions.

Needle aspirations of benign and malignant epithelial lesions of the thyroid were investigated in 265 patients. An 18-gauge needle connected to a 20-cc glass syringe was used to puncture each tumoral mass. Smears were stained by the Wright-Giemsa method. The material obtained consisted of 180 nontoxic goiters, 18 toxic goiters, 15 cases of thyroiditis and 52 malignant lesions. Aspirations taken from 21 patients (8%) were either blank or contained only blood and insufficient material for diagnosis. Results were correlated with clinical findings and laboratory tests. Biopsies were obtained only in selected patients to establish the final diagnosis. One false positive and one false negative were recorded. Although well-preserved follicular patterns can be seen on the cytologic specimens, the differentiation of thyroid adenoma from early follicular carcinoma based on cytologic criteria only if fraught with many difficulties. Cell density, nuclear structure and presence of nucleoli are sometimes helpful in making the cytologic diagnosis of thyroid carcinoma.