combination of aspiration and non-aspiration fine needle biopsy for cytological diagnosis of thyroid nodules

background: good cytological sample is very important for the cytological diagnosis of thyroid nodules. the aim of this study was to evaluate the adequacy of prepared samples by the combination of aspiration and non- aspiration fine needle biopsy. methods: in this descriptive – analytical study, sampling was done simultaneously for each patient in fine needle aspiration and non-aspiration biopsy. the sufficiency of samples was studied using mair scoring system. wilcoxon signed rank test was used for the data analysis. results: three hundred two cases (289 females, 13 males) with the mean age of 43.83±12.9 years were evaluated. inadequate samples were 31 (10.3%) in fine needle aspiration, 40 (13.2%) in non-aspiration and 13 cases (4.3%) by using two methods together (p=0.0001). the average total score was 6.00±2.17 in fine needle aspiration and 5.76±2.26 in non-aspiration method (p=0.08), and 6.6±1.98 in the combination of the two methods (p<0001 comparing with one method alone). conclusion: the results show that using both methods simultaneously in each nodule considerably increases the efficiency of samples for cytological diagnosis.