Predictors of Malignancy in Patients with Solitary and Multiple Thyroid Nodules

Abstract

Introduction: Ultrasound (US) and Fine-needle aspiration (FNA) are the main methods used for investigating thyroid nodules, with questionable predictive values in multinodular goiter (MNG) compared to solitary thyroid nodule (STN). Objective: To detect the independent predictors of malignancy in patients with solitary and multiple nodules. Patients and Methods: Medical records of patients who were admitted for thyroidectomy at Alexandria Main University Hospital and Medical Research Institute Hospital between January 2014 and January 2016 were reviewed. Demographic and clinical data, US reports, FNA reports (Bethesda “B” system), and final histopathological results were recorded and analyzed. Patients with hyper- or hypo-thyroidism, previous history of thyroid cancer or those with incomplete data were excluded. Results: Collectively, 20% (111/554) of the study population proved to have malignancyon final histopathology, 19.3% (82/422) with MNG and 22% (29/132) with a STN. Combining gender and age showed that significantly more male patients with MNG under the age of 45 years had thyroid cancer (X2=11.75, p=0.003).Statistically significant US features in the MNG Group included micro-calcifications, solid composition, echogenicity, incomplete halo, ill-defined margins, and suspicious cervical lymph nodes (LNs). In STN, significant US features included complex composition of nodules, peri-nodular vascularity, and also suspicious cervical LNs. The FNA results of BII-V reports showed that 16.9% (69/408) and 17.6% (22/125) of patients with MNG and STN, respectively, had false negative results. The risk of malignancy showed a significant rise from BIV to BVI lesions in both Groups. Multivariate analysis revealed that, in MNG, the highest malignancy predictor was micro calcification, followed by FNA (BVI) and then suspicious cervical LNs. In STN, the features that retained significance in multivariate analysis were suspicious LNs& BVI-FNA. Conclusion: Based on the data presented, it may be concluded that the independent predictors of malignancy were US findings of micro-calcification in patients with MNG, suspicious cervical LNs and Bethesda VI on FNA in patients with both MNG and STN.