ABSTRACT
Fine-needle aspiration cytologic smear of 30 cases of papillary thyroid carcinoma was examined in a trial to distinguish preoperatively between the usual non-aggressive [classic, follicular and mixed papillary and follicular variants] and the aggressive [tall- cell, columnar cell and sclerosing diffuse] variants of papillary thyroid carcinoma. The cases were classified according to a grading system based on the evaluation of four cytologic parameters into cell size, number of nuclear pseudoinclusions, nuclear pleomorphism and type of chromatin. A significant association between the cytologic classes and the histologic features of the cases was found. All cytologic grade I cases corresponded to the non-aggressive histologic variants, whereas, all cytologic grade III cases showed features of the aggressive variants of papillary thyroid carcinoma at the histologic level