The usefulness of computer-aided karyometric examination in preoperative differentiation of follicular neoplasms of the thyroid gland.

Fine-needle aspiration biopsy (FNAB) is the most important procedure in preoperative diagnosis of thyroid neoplasms. However, routine cytological examination is insufficient for differentiation between follicular adenoma and follicular carcinoma. Therefore, we decided to assess the usefulness of karyometric analysis in the examination of aspirates from these neoplasms. Morphometric analysis was performed with the use of the computer system for karyometric measurements--"Karyometry Manager" ver. 1.2. We examined cytological smears derived from 26 patients. In 10 of them a nodular goitre was diagnosed in both cytological and histopathological examinations. In the other 16 patients, "follicular neoplasms" were found in cytological examination. These proved to be follicular adenomas (8 cases) and follicular carcinomas (8 cases) on histopathological examination. The following morphometric parameters were measured in 100 nuclei per smear: volume, intersection area, perimeter, convexity coefficient and shape coefficient. We found that: 1) the mean volume and the mean intersection area of thyrocyte nuclei from follicular carcinomas were significantly (p < 0.001) greater than those of nuclei from adenomas or nodular goitres; 2) the mean perimeter of thyrocyte nuclei from follicular carcinomas was significantly greater than the mean perimeter of thyrocyte nuclei from follicular adenomas (p < 0.025) and nodular goitres (p < 0.001); 3) the mean nuclear area of thyrocytes from follicular adenomas was significantly greater than that of thyrocytes from nodular goitres (p < 0.05). Our results show that karyometric analysis can be useful in cytological differentiation of follicular neoplasms.