The relationship between thyroid volume and malignant thyroid disease

The present retrospective study aimed to investigate the relationship between thyroid volume and prevalence of thyroid cancer. We investigated the data of 3,850 patients who underwent fine-needle aspiration biopsy (FNAB). Biopsy results were evaluated as diagnostic or nondiagnostic, and diagnostic results were classified as benign, malignant, and indeterminate. We included 2,672 patients who underwent FNAB firstly in our hospital and evaluated as diagnostic biopsy except subgroup of indeterminate. We obtained cytologic data, levels of serum thyroid-stimulating hormone (TSH), and thyroid volumes of those patients retrospectively. Among 2,672 patients with thyroid nodule, 2,562 (95.9 %) patients had benign cytology and 110 (%4,1) patients had malignant cytology. There was no correlation between the malignancy and gender (p = 0.935), and patients with malignant cytology were younger (52 vs 59, p < 0.001). Also, TSH levels were higher in patients with malignant than benign cytology (p = 0.017). Median volume of right part, left part, and total thyroid for patients who had malignant cytology was significantly lower than patients who had benign cytology (8.3, 7.1, 15.9 vs 10.8 ml, 9.0 mml, 20.6 ml, respectively, p ≤ 0.001 for all parameters). The results demonstrated that thyroid cancer prevalence was higher in patients with low thyroid volume. According to our results, thyroid volume should be considered as a risk factor for malignancy in the evaluation of thyroid nodules.