AgNOR quantification in the diagnosis of follicular pattern thyroid lesions.
OBJECTIVE
To evaluate the usefulness of silver staining of nucleolar organizer regions (AgNORs) in the preoperative diagnosis of follicular lesions in the thyroid with computer-aided morphometric analysis of the silver dots.


METHODS
Forty-eight cytologic smears of the thyroid were divided into 3 groups according to the results of postoperative histopathologic examination: hyperplastic nodules in nodular goiter (NG) (20), follicular thyroid adenoma (FTA) (20) and follicular thyroid carcinoma (FTC) (8). They were silver stained. The slides were analyzed with a computerized system for image analysis. Nearly 20 variables describing AgNORs were calculated (related to the area of the dots, number of dots and intranuclear localization of the dots).


RESULTS
Only assessment of the total area of AgNORs in the nucleus allowed distinguishing between malignant and benign lesions. It was possible to determine the cutoff value of the total area of AgNORs in the nucleus (3.00 microns 2), limiting FTC from other lesions (observed ranges: NG, 1.64-2.87 microns 2; FTA, 1.81-2.85 microns 2; FTC, 3.01-3.97 microns 2). Evaluation of the mean number of AgNORs per nucleus did not improve the diagnosis of malignancy.


CONCLUSIONS
Computer-aided morphometric analysis of silver dots may be useful in the preoperative diagnosis of thyroid lesions.
Słowińska-Klencka
Dorota
D
Departments of Thyroidology and of Endocrinology and Isotope Therapy, Institute of Endocrinology, Medical University of Łódź, Dr. Sterling St. 5, 91-425 Łódź, Poland. dsk@tyreo.am.lodz.pl
Klencki
Mariusz
M
Popowicz
Bozena
B
Lewiński
Andrzej
A
D018263:Adenocarcinoma, Follicular / Q000175:diagnosis / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D009697:Nucleolus Organizer Region / Q000473:pathology*; D016622:Silver Staining; D013964:Thyroid Neoplasms / Q000175:diagnosis / Q000473:pathology*