Background: Fine-Needle Aspiration (FNA) is the main screening process for distinguishing benign from malignant thyroid nodules. Despite this, by 5-29% of patients, their FNA results are not enough to confirm malign neoplasia, particularly in cases with follicular lesions. The objective of this report is to present the definitive histological results of a group of 41 patients with FNA of Thyroid nodule catalogued as "indeterminate/non diagnostic" sent for surgical treatment.
Material and methods: A retrospective analysis was done on all of the patients who had underwent surgery for thyroid nodule, with a previous diagnosis of "indeterminate/non diagnostic" by FNA. Forty-one patients, three male (7.31%), and 38 female (92.68%), were included in the present study.
Results: Fifteen women and one man were positive for malignancies (39.02%). The nodule was bigger than 4 cm in 23 patients in total (56.09%), and of this percentage, 6 were malignant (26.09%). According to age, 24 patients were older than 45 years (58.5%), 8 of whom showed malignant pathology (33.3%). All these variables were non significant. Fifteen of 16 patients had a definitive diagnosis of papillary carcinoma and one follicular carcinoma.
Conclusions: The majority of patients with a diagnosis of "indeterminated/non diagnostic" had benign lesions (60.9%). The usual predictive factors for malignity such as age, sex, size of nodule, did not present a significant support in the differential diagnosis.