Ultrasound and Fine Needle Aspiration Cytology Correlation of Thyroid Nodules

Purpose: High resolution grey scale ultrasound has emerged as an initial imaging modality of choice for the evaluation of patients with thyroid enlargement. Thyroid malignancy cannot be diagnosed on ultrasonography but various sonographic features in combination can be used to predict malignancy in thyroid lesions. The aim of our study was to evaluate the diagnostic accuracy of ultrasonographic features for the differentiation of benign and malignant thyroid nodules by using FNAC as the reference standard. Materials And Methods: The present study was a prospective study of 200 consecutive patients more than 10 years of age who attended various OPD’s and IPD’s of SKIMS Soura with thyroid nodules. A high-resolution grey scale sonography of the thyroid gland was performed along with a color-flow Doppler study. Sonographically guided FNAC was then performed by the standard technique. Pre-FNAC sonograms were interpreted with respect to number of nodules, nodule size (largest diameter of largest nodule, if more than one), echogenicity, echo structure, shape, border characteristics, presence or absence of calcifications, and vascularity on color flow Doppler examination. All statistical calculations were performed using a 2 ×2 contingency table and χ2 analysis. Data associations were considered statistically significant at p< 0.05. Results: Mean age was 38.91 years ±10.85 years. There were 47 males and 153 females with a male: female ratio of 1:3.26. Overall, majority (94%) of nodules were benign predominated by colloid nodules. Malignant nodules accounted for 6% of cases, out of which papillary carcinoma was most common. Microcalcifications, irregular/ill-defined margins, hypoechogenicity, taller than wide shape, and internal vascularity were the sonographic features found to be significantly associated with malignancy. Conclusion: As per our results, the best compromise between risk of missing carcinomas of potential clinical aggressiveness and the need to avoid unnecessary procedures is to use FNAC on nodules with at least one of the high-risk sonographic features.