Endocrine Abstracts

The prevalence of thyroid nodules is increased in the elderly. The aim of this study was to evaluate the accuracy of US and US-FNAB in the diagnosis of thyroid cancer in a population of elderly subjects, all of whose thyroid nodules were subjected to US-FNAB, with no prior selection based on dimensions or echo-pattern. Over a three-year period, 276 consecutive patients (64 males and 212 [76.8%] females), aged 65 to 87 (mean 70±4.4), underwent US evaluation and US-FNAB of all their thyroid nodules. A total of 507 nodules were analyzed. Diameter: 5 to 70 mm (19.7±12 mm). Solitary in 97 cases (19.1%), more than one in 410 cases (80.9%). Echographic pattern: hypoechoic in 255 cases (50.3%), isoechoic in 147 (29%), hyperechoic in 46 (9.1%), anechoic in 19 (3.7%), mixed in 40 (7.9%). Halo was present in 194 cases (38.3%). Microcalcification in 64 cases (12.6%). Cytology: negative in 448 nodules (88.4%), suspicious or indeterminate in 11 (2.2%), positive in 27 (5.3%), non-diagnostic in 21 (4.1%). Twenty-two patients underwent surgery (8%): 13 carcinomas (10 papillary, 2 anaplastic, 1 medullary), and 9 struma/adenomas. A total of 44 excised nodules were finally examined: 17 hyperplastic nodules (38.6%), 3 adenomas (6.8%), 24 carcinomas (54.5%): 19 papillary, 4 anaplastic and 1 medullary carcinoma. Malignant nodules were solitary in 8.3%; more than one in 91.7%; benign nodules were solitary in 10%, more than one in 90% (NS). Malignant nodules were hypoechoic in 21 (87.5%), isoechoic in 3 cases (12.5%). Benign nodules were hypoechoic in 6 cases (30%), isoechoic in 12 cases (60%), mixed in 2 (10%) (P<0.0005). A hypoechoic pattern had 87.5% sensitivity, 70% specificity and 79.5% accuracy in the diagnosis of thyroid cancer. A halo sign was present in 12.5% of malignant nodules vs 40% of benign nodules (P<0.04). The absence of a halo sign had 87.5% sensitivity, 40% specificity and 66% accuracy in the diagnosis of cancer. Microcalcifications were present in 12.5% of malignant and 10% of benign nodules (NS) (sensitivity 14%, specificity 90%, accuracy 48%). A hypoechoic pattern, microcalcifications and absence of a halo were simultaneously present in 1/20 benign nodules (5%) and in 3/24 malignant nodules (12.5%) (NS). Diameters were not statistically different (M:21.5±14.3 vs B:19.4±8.8 mm). For positive and suspicious or indeterminate cytological results considered in the same category, US-FNAB had 100% sensitivity, 100% specificity and 100% accuracy in this group of subjects.