Diagnostic efficacy of fine needle aspiration biopsy in patients vAth thyroid nodular disease.: Analysis of 510 cases

Introduction. The prevalence of palpable thyroid nodules in the general population is 4%-7%. Although most are benign, 5% are carcinomas. This study aimed to assess the efficacy of fine needle aspiration biopsy (FNAB) of thyroid nodules to diagnose malignancy and know the benefit of repeating the FNAB in the same nodule. Patients and methods. A total of 510 patients (431 women and 79 men; mean age [standard deviation]: 47.6 [14.3] years) with surgery due to thyroid nodular condition between 1989 and 2002 and who had at least one FNAB prior to the surgery were studied. Results. The first FNAB was benign in 312 patients (61.2%), malignant in 38 (7.5%), suspicious or indeterminate in 97 (19%) and insufficient in 63 (12.4%). Sensitivity and specificity in the first FNAB for malignancy diagnosis was 76% and 84%, respectively. Successive FNABs had a moderate concordance and significance. However, repeating the puncture did not improve diagnostic performance, since sensitive increased (84%), but specificity worsened (79%) and the area under the ROC curve was similar. In the group with suspicious or indeterminate FNAB, histology was benign in 70% and malignant in 30%. Conclusions. FNAB sensitivity and specificity for diagnosis of malignancy in thyroid nodules are high. Repetition of puncture on the same nodule does not improve diagnostic performance of the cytology. Among patients with suspicious FNAB, there is a high proportion of malignancy, which makes surgery necessary in these cases.