The value of histomorphometric nuclear parameters in the diagnosis of welldifferentiated follicular carcinomas and follicular adenomas of the thyroid gland

Aims: To explore the potential of histomorphometric analysis in distinction between follicular adenomas and well differentiated follicular carcinomas of the thyroid gland. Their differentiation on routine histological study m ay be a challenging exercise, being contingent upon the absence or presence of vascular invasion and penetration of neoplastic follicles through the c apsule of the tumour. Methods and results: Computer-assisted image analysis was performed to gaug e the nuclear area, nuclear Ferret diameter, nuclear regularity factor, nuc lear elongation factor, number of nuclear vesicles and total area of all nu clear vesicles in the follicles of 37 adenomas and 36 well differentiated c arcinomas. By univariate analysis, these nuclear descriptors (with the exce ption of the elongation factor) were found to correlate with the benign or malignant nature of the tumours, By multivariate analysis, only the nuclear area, Ferret diameter and regularity factor were ascertained to be signifi cant predictors of malignancy. A fitted logit model correctly predicted 91% of the cancers and 87% of the adenomas. Conclusions: Histomorphometrically gauged nuclear parameters of the tumour cells may reinforce pathologists' decision-making by adding objective and u nbiased criteria to their subjective assessment of follicular neoplasms in cases in which vascular or capsular invasion are not detected.