Risk of Malignancy in Thyroid Incidentaloma is Not Increased in Overweight or Obese Patients, but in Young Patients.

Thyroid incidentaloma is defined as an unsuspected, asymptomatic thyroid lesion that is discovered on an imaging study or during an operation unrelated to the thyroid gland. We aim to evaluate the relationship between overweight or obese and risk of malignancy in patients with thyroid incidentaloma detected by F18-flurodeoxyglucose positron emission tomography/computed tomography and factors to predict risk of malignancy in thyroid incidentaloma. From January 2010 to December 2013, a total of 238 patients were eligible for this study. Using the Bethesda system for reporting thyroid cytopathology, categories I-III were defined as a nonmalignancy and categories V-VI were defined as a malignancy. When patients with body mass index (BMI) of less than 23 and 23 or more were divided into two groups of normal and overweight or obese, risk of malignancy of thyroid incidentaloma was not significantly different between two groups (P = 0.1812). In logistic regression analysis, age was the only variable that showed a significant association with malignancy of thyroid incidentaloma (odds ratio 0.9608, P = 0.0021). However, none of sex, height, weight, and BMI was predictor of malignancy of thyroid incidentaloma. We demonstrated that being overweight or obese did not increase rate of malignancy in patients with thyroid incidentaloma.