Efficiency of Fine Needle Aspiration Cytology of Thyroid Nodule in Diagnosing Malignancy

Abstract

Introduction: A thyroid nodule is a common presentation of thyroid disease; the estimated incidence of solitary palpable thyroid nodules in the adult population of the United States varies between 1% and 10%. Fine needle aspiration cytology (FNAC) is the first line diagnostic tool in both solitary and dominant thyroid nodules. Objectives: This study aimed to evaluate the role of FNAC in diagnosing malignancy in solitary thyroid nodule. Methododology: This descriptive pro and retrospective study about the role of fine needle aspiration cytology examination in the diagnosis of solitary thyroid nodule and it`s co-relation with the final histopathological results. The study was carried out during the period June 2009-August 2010, in the three main histopathology laboratories in Khartoum. Fifty cases of thyroid nodules were studied, thirty eight of them were retrospective and twelve were prospective. Sensitivity, specificity and efficiency of the fine needle aspiration cytology in diagnosing malignancy were determined. Results: The age of the patients ranged between 18 -84 years with a mean of 47.56 years. The commonest age group was 30 – 40 years (24%). The M: F ratio was 1:2. The fine needle aspiration cytology results were malignant in 64% while histopathology results were malignant in 76% with 78% results showing co-relation. In addition to that, cell block results showing 100% correlation with histopathology results. Fine needle aspiration cytology sensitivity was 78.3%, specificity 84%, efficiency 80%. The study showed that follicular carcinoma was the most common III diagnosis by fine needle aspiration cytology, it accounts for 32% followed by papillary carcinoma 24%. The histopathology results were 24% and 22% for follicular and papillary carcinoma respectively. Conclusion: When all the findings in the study were compared together, the efficiency, sensitivity and specificity of the fine needle aspiration cytology tend to be comparable with other studies, in Sudan and elsewhere.