Fine-needle aspiration biopsy possibilities and limitations
Delia Ciobanu1, Carmen Vulpoi1, Niculina Florea2, Lidia Andriescu1, Alexandru Grigorovici1, Voichita Mogos1, Bogdan Galusca1, Cristina Cristea1, Letitia Leustean1 & Eusebie Zbranca1
The critical problem of thyroid nodules is to identify the malignant ones Fine needle aspiration biopsy (FNAB) plays a crucial role in this diagnosis and enables the number of surgical operations to be reduced. We have evaluated the performances of FNAB in comparison with the histological examination in 1971 consecutive patients who suffered both fine-needle puncture and surgery in a 5 years interval at a University Hospital. FNAB was malignant or suspicious in 8.4% patients, and the histology confirmed thyroid cancer in 8.7% (confirming all those diagnosed by FNAB). Statistical analysis revealed a sensitivity of 77% and a specificity of 95%, better than the admitted inferior limit of the literature data (71% respectively 72%). Papillary thyroid carcinoma was the easiest to diangose by the cytology, the efficacy of the method being 97%. For anaplastic and medullary carcinoma, FNAB is a good method to diagnose the malignancy (concordance of 97%) but has not the capacity to confirm the type of the neoplasia. In the follicular carcinoma, the positive predictive value is lower than for the other forms (27% vs 99%) although the efficacy is not significantly modified (94%). These data justify the introduction of morphometric methods and of the cytochemistry, able to enhance the accuracy of FNAB. These methods are time-consuming and we were using them only in controversial cases. With a very good sensitivity and specificity, FNAB is a reliable method of diagnosis in thyroid nodules, easy to perform and permitting to avoid unnecessary surgery.