Diagnostic value of colour Doppler ultrasound in differentiating malignant and benign nodules in thyroiditis background.

INTRODUCTION: Differentiating malignant thyroid nodules from benign ones is challenging. Sonography is a non-invasive modality that can be helpful in this regard and is far better than invasive methods like fine needle aspiration (FNA). This study aimed to assess the diagnostic value of colour Doppler ultrasonography in distinguishing malignant and benign nodules of thyroid gland.

METHODS: The study involved patients with thyroiditis and thyroid nodules, who underwent sonography. Ultrasound findings were assessed. All the nodules were classified according to the FNA into malignant, follicular nodules and lymphatic. Then, sonography findings were compared between these three groups.

RESULTS: There were 216 nodules, including 108 (50%) malignant nodules, 80 (37%) benign and 28 (13%) lymphatic follicles, were evaluated. Micro-calcification was present in 50 (46.3%) malignant cases, 11 (13.7%) benign cases and 2 (2.1%) lymphatic follicles. Decreased or mixed vascularity was reported in 43 (69%) malignant nodules, 4 (5%) benign cases and 7 (25%) lymphatic follicles. Also, 9.7% and 42% of malignant and benign nodules had peripheral circular vascularity, respectively; however, none of the lymphatic follicles had this finding. With 89% specificity, 49% sensitivity and 73.5% accuracy, calcification with or without decreased or mixed vascularity could differentiate benign and malignant nodules.

CONCLUSION: Decreased or mixed vascularity with or without calcification shows high sensitivity in differentiating malignant and benign nodules.