A Comparison of aspiration and non- aspiration fine needle techniques in providing standard amount of follucular cells for cytodiagnosis of thyroid nodules at Mulago hospital

Abstract

Introduction: Fine needle cytology is recommended as the initial evaluation of thyroid nodules. Its main limitation are inadequate cellular harvest and indeterminate results. Unpublished cytology results of January 2006 to April 2006, of mulago hospital- Uganda, showed that about 50% of specimen were inadequate. The question of whether to use the aspiration (FNA) or non-aspiration (FNNA) technique in biopsying thyroid nodules to overcome this problem of inadequate cellular harvest remains with us. Objective: To compare FNA and FNNA techniques of thyroid nodules, in improving the standard amount of follucullar cells for cytodiagnosis (SAFC) at mulago hospital. Methods: In a cross sectional study, 100 thyroid nodules were categorised by their widest diameter into <1cm, 1-4cm, >4cm. Both FNA and FNNA were performed on each nodule. After papanicolaou and Diff-Quik staining, the follicular cells harvested were quantitatively analysed for the SAFC by a cytopathologist blinded to the biopsy technique used and compared using wilcoxon signed ranks test and McNemar’s test statistic. Results: The patients’ age range was 19 to 70 years ( mean 43 years) and 95.5% were females. Regarding the provision of the SAFC: FNNA had a higher mean cell count than FNA (108 vs 63), p=0.001; the proportion of specimen providing SAFC with FNNA was 0.894 vs 0.765 with FNA, the difference between proportions = 0.1290, ( 95% CI 0.053-0.206); FNNA was superior to FNA, OR= 6.5 (95% CI=1.57-26.9), P<0.01; and there was no significant difference between the nodules of diameter >4cm and 1-4cm, using FNNA(OR= 0.77, 95%CI 0.14-3.85, P=0.72) or FNA (OR= 0.81, 95%CI 0.25-2.26, P= 0.689). Conclusion and recommendation: The findings suggest that with regard to the provision of the standard amount of follicular cells for cytodiagnosis of thyroid nodules at mulago hospital: FNNA was superior to FNA technique and there was probably no statistically significant association with the diameter of the thyroid nodules for cytodiagnosis of thyroid nodules at mulago hospital to reduce the rate of inadequate specimen and, a randomised controlled trial to compare FNA and FNNA.