Malignancy rates and risk factors in Bethesda category IV thyroid nodules: Is lobectomy enough in an endemic region?

Abstract

In this paper, we determined the rates of Bethesda IV thyroid nodules and we calculated the malignancy rates of these nodules in a university hospital located in an endemic area for thyroid diseases. We aimed to define the predictive factors for malignancy to select patients who need surgery. Between January 2012 and December 2018, 221 patients who had preoperative biopsy as follicular neoplasm/suspicious for a follicular neoplasm and underwent thyroidectomy were included in the study. The datas about patient characteristics, preoperative ultrasound results indications for operation and postoperative pathologicale valuation results were evaluated. Index and incidental malignancy rates were calculated. The malignancy rate of index Bethesda Category IV nodules was 48.9 %. Incidental malignancy rate was 30.7 %. There was no statistical difference between patients who had benign and malignant pathology results in terms of gender, age, preoperative diagnosis, size of the index nodule, number and results of biopsies and the operation performed. The most important risk factor among all parameters was hypoechogenicity of the nodule. Solid structure increase this risk. Ultrasonographic hypoechogenicity is the most important risk factor for preoperative malignancy risk assessment for Bethesda Category IV thyroid nodules. Centers should determine their malignancy rates with particular risk factors and determine their surgical approaches in endemic regions.

Keywords

• Bethesda category IV nodules
• follicular neoplasm/suspicious for follicular neoplasm
• thyroid nodules

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