Incidental Thyroid Malignancy in Surgical Patients With Benign Thyroid Disease.

Introduction: The rate of incidental thyroid malignancy (ITM) has increased in recent decades. However, the factors associated with ITM remain uncertain. This study analyzes the rate of ITM in patients after surgical resection for benign thyroid disease (BTD) without preoperative suspicion of thyroid malignancy and its associated sociodemographic factors.

Materials And Methods: A retrospective study of prospectively collected data reviewed data from 2528 patients who underwent initial thyroidectomy for BTD at a tertiary academic medical hospital between 2011 and 2022. Patients were excluded if they had a known history of thyroid cancer, radiation exposure, suspicious thyroid ultrasound features, and/or fine needle aspiration results. ITM rate was analyzed along with patient demographics, body mass index (BMI), tumor size, and invasive features.

Results: Among 345 patients with BTD (mean 53.6 y, SD = 14.5), 22.9% (79/345) had ITM on final histopathology. Most patients were women (87.0%), White (87.0%), and Hispanic (56.8%), with an average BMI of 29.6 (SD = 6.56). BTD type was associated with ITM (P < 0.001), with nontoxic multinodular goiter exhibiting the highest incidence (36.0%). Higher BMI emerged as a predictor of higher rate of ITM (OR = 1.057, P = 0.007). Other sociodemographic variables did not show significant associations.

Conclusions: The study identified a higher rate of ITM than previously reported as well as an association between higher BMI and increased rate of ITM. This highlights a potential link between obesity and ITM not previously identified. Patients with higher BMI and BTD may benefit from further surveillance.