Endocrine Abstracts

Aim of this study was the evaluation of the accuracy of ultrasound and US-FNAB in the diagnosis of thyroid cancer in a population of subjects submitted to US-FNAB of all thyroid nodules, with no prior selection. 1803 patients (1447 females e 356 males, age range 11 – 87 years, mean 49.6±13.7, with a total of 3378 nodules) were submitted by the same physician (first author) to ultrasound evaluation and US-FNAB of all thyroid nodules. Results. The nodules were 3 to 90 mm in diameter (17.9±10.9); solitary in 708 cases (39.3%), 2 or more nodules in 1095 cases (60.7%); echographic pattern: hypoechogenic in 51%, isoechogenic in 29%, hyperperechogenic in 7%, anechogenic in 5%, mixed in 8%; alo sign was present in 39.3%; microcalcification in 10.8% of cases. Cytology was negative in 3024 nodules (89.5%), suspicious or indeterminate in 97 (2.9%), positive in 111 (3.3%), non-diagnostic in 146 (4.3%). 170 patients underwent to surgery (9.4%): 79 carcinomas (71 papillary, 2 follicular, 3 anaplasic, 2 medullary, 1 Hurthle cells), often plurifocal, and 91 struma/adenomas. A total of 345 nodules were finally examined: 188 iperplasic (54.4%), 33 adenomas (9.6%), 124 carcinomas (36%; 113 papillary, 2 follicular, 5 anaplasic, 2 medullary, 2 Hurthle-cells). US-FNAB had 87% sensitivity, 91% specificity and 90% accuracy. Malignant nodules were solitary nodules in 26.6%; more than one nodule in 73.4%; benign nodules were solitary in 17.6%, 2 or more in 82.4% (P<0.05). Malignant nodules were hypoechogenic in 79%, isoechogenic in 10.6%, hyperechogenic in 3.2%, anechogenic in 4%, mixed in 3.2%. The percentages for benign nodules were respectively: 44.7%, 34%, 8.6%, 4.1%, 8.6% (P<0.0005). Hypoechogenic pattern had 79% sensitivity, 56% specificity and 64% accuracy in the diagnosis of cancer. Alo sign was present only in 13.7% of malignant nodules vs 46.2% of benign nodules (P<0.0005). The absence of alo sign had 86% sensitivity, 46% specificity and 61% accuracy in the diagnosis of cancer. Microcalcifications were present in 25% of malignant and 11.3% of benign nodules (P<0.001) (sensitivity 14%, specificity 89%, accuracy 66%). Diameters were not statistically different (19.6±13.3 vs 20.7±11.4 mm). Our data confirm that there isn’t any echographic sign that has sufficiently high sensitivity and specificity to substitute US-FNAB in the diagnosis of thyroid cancer.