Endocrine Abstracts

Introduction: Follicular neoplasm (FN) or suspicious for a follicular neoplasm category is established by The Bethesda System for Reporting Thyroid Cytopathology because of the necessity to identify a nodule that might be a follicular carcinoma and triage it for surgical lobectomy. Estimated risk of malignancy for this category is 15–30%.

Description of methods: We conducted a retrospective study that included all patients with a follicular neoplasm result after thyroid fine-needle aspiration (FNA) between 2010 and 2014. The following variables were considered: age, necessity of surgery and type of procedure (total or partial thyroidectomy), malignancy incidence rate.

Results: We studied 97 patients (85.6% female; mean age 53±15 years). Thyroidectomy was performed in 62.9% of all patients. Lobectomy was the selected procedure in 32.8% of cases. 67.2% of patients underwent total thyroidectomy. The incidence of malignancy was 16.4% of patients who underwent surgery (13.2% of the total sample). Of those that proved to be malignant two Hurthle cell carcinomas, one papillary carcinoma, one follicular carcinoma and two medullary carcinomas were found. In 4 cases incidental papillary microcarcinoma were discovered after surgery. 19.6% of benign lesions were follicular adenomas.

Conclusions: Follicular neoplasm or suspicious for a follicular neoplasm category is a useful tool for classifying those thyroid FNA that may be suspicious for follicular carcinoma and may help selecting patients that should undergo surgery. The incidence of malignancy detected in our series is consistent with the incidence expected by the Bethesda System for Reporting Thyroid Cytopathology.