RESUMEN
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.
