MORPHOMETRY IN THE CYTOLOGIC EVALUATION OF THYROID FOLLICULAR LESIONS

BACKGROUND. The current study was undertaken to evaluate the quantitat ive estimation of cytologic features on aspirated smears for the preop erative differential diagnosis of follicular lesions of the thyroid. M ETHODS. The subjects were 60 patients with follicular lesions of the t hyroid (including 20 follicular carcinomas, 15 follicular adenomas, an d 25 adenomatous goiters) whose histopathologic explorations were cond ucted fully postoperatively. Using a microscope connected to a compute rized video system, the mean nuclear area, the mean nuclear perimeter, the circular rate, the largest to the smallest dimension ratio (LS ra tio) of the nuclei, and the coefficient of variation of the nuclear ar ea (NACV) were measured and analyzed. RESULTS. Among the quantitative morphometric parameters of nuclei, the circular rate was significantly higher in the group with adenomatous goiters than those with follicul ar carcinomas (P < 0.00001) and adenomas (P < 0.005). The group with f ollicular carcinomas had a higher LS ratio than the group with adenoma tous goiters (P < 0.0005). The NACV value increased as the malignant p otential of the lesion increased and showed significant differences be tween the groups. When a NACV of 21.5% was chosen as the cutoff point, the incidence of malignancy was significantly higher in patients with high NACV values than in those with low NACV values (P < 0.00001). Us ing this borderline value, it was possible to distinguish malignant fr om benign diseases with a sensitivity of 85.0%, a specificity of 82.5% , and an accuracy of 83.3%. CONCLUSIONS. Preoperative quantitative est imations of cytologic nuclear features are useful for the preoperative differential diagnosis of follicular lesions of the thyroid. (C) 1998 American Cancer Society.