Combined Ultrasound and Needle Aspiration Cytology in the Assessment and Management of Hypofunctioning Thyroid Nodule

Abstract

We evaluated the efficacy of combining B-scan bistable and gray-scale ultrasound with needle aspiration cytology in assessing and managing solitary hypofunctioning solid and cystic nodules. Of the 150 cases surveyed, 90 had surgical follow-up histology for comparison to preoperative aspiration cytology results. Overall neoplasm rate in these 90 cases was 66%, increasing to 93% if colloid nodules were included. Adequate material for cytology preoperatively was obtained in 83 (92%). In cases with adequate preoperative needle aspiration cytology, there were 66 solid and 17 cystic or mixed lesions. Overall accuracy for differentiating benign from malignant nodules for solid lesions was 63 of 66 (95%), compared to 15 of 17 (88%) for predominantly cystic or mixed lesions. Of the 17 cases of proven carcinoma, correct preoperative cytology diagnosis for malignancy was obtained in 12 (71%). Malignancy was most often correctly diagnosed for solid papillary and metastatic cancer lesions. No false-positives were noted and atypical adenomas and Hürthle-cell adenomas have been correctly diagnosed. The simplicity and safety of these diagnostic procedures justify their use for "selective" surgery and particularly for those cases that have been initially assigned to conservative, nonsurgical therapy.