Follicular neoplasms of the thyroid: importance of clinical and cytological correlation.

BACKGROUND

Thyroid cancer presents as nodules. Thyroid nodules are frequent, but only 5-30% are malignant. Fine needle aspiration biopsy (FNAB) is useful for initial evaluation; nevertheless, malignancy is uncertain when follicular neoplasm is reported. Some factors can be associated with malignancy. Therefore, we analyzed our follicular neoplasms in order to identify those factors associated with a higher risk of malignancy.

METHODS

We analyzed the clinical files of consecutive patients with cytological diagnoses of follicular neoplasm.

RESULTS

From 1,005 cases of thyroid nodules, 121 were follicular neoplasms according to cytology. Of these, 75 were surgically treated. Definitive report showed 45 benign (60%) and 30 malignant (40%) cases. Benign cases included 29 goiters, 11 follicular adenomas, and 5 cases of thyroiditis. Malignant cases were comprised of 12 papillary carcinomas, 4 follicular carcinomas, 3 papillary carcinomas-follicular variant, 1 lymphoma, 1 teratoma, 5 medullary carcinomas, 2 insular carcinomas, 1 anaplastic carcinoma and 1 metastatic breast carcinoma. Tumor size of benign lesions was 3.43 ± 2.04 cm, and 4.67 ± 2.78 (p = 0.049) for malignant lesions. Age was 46.95 ± 15.39 years for benign lesions and 48.67 ± 17.28 for malignant lesions (p = 0.66). Fifty percent of males showed malignancy vs. 37.7% of females (p < 0.005).

CONCLUSIONS

Our results suggest that size and gender, but not age, are associated with cytological pattern. Ultrasonographic characteristics may be useful discriminating patients with a higher risk of malignancy. FNAB is a useful tool for initial evaluation of thyroid nodules, but clinical evaluation can enhance predictive value.