KARYOMETRIC ANALYSIS IN THE CYTOLOGIC DIAGNOSIS OF THYROID LESIONS

OBJECTIVE: To assess the possible role of karyometry in improving the diagnostic value of fine needle aspiration biopsy (FNAB) of the thyroi d. STUDY DESIGN: Thyrocyte nuclei were evaluated in routine slides obt ained from 229 patients. The cytologic specimens were divided into sev en groups according to the results of corresponding postoperative hist opathologic examinations. Karyometric measurements comprised assessmen t of nuclear volume, intersection area and perimeter as well as level of anisokaryosis, evaluated as standard deviations of those parameters in single slides. The karyometric evaluation was performed with a com puterized image analysis system. RESULTS: The size of thyrocyte nuclei increased from nontoxic nodular goiters through follicular adenomas, toxic nodular goiters treated with antithyroid drugs, lymphocytic thyr oiditis, papillary and follicular carcinomas to anaplastic carcinomas. The observed differences between those groups were statistically sign ificant, but there wits marked overlapping Our data indicate also that the age and sex of the patient influence the cytologic picture of nod ular goiter. The evaluation of anisokaryosis increases the usefulness of karyometry in differentiating malignant neoplasms from benign lesio ns. CONCLUSION: Karyometric analysis increases the probability of a co rrect diagnosis with FNAB examination.