Comparison of Fine Needle Aspiration Cytology (FNAC) and thyroid ultrasonography in the diagnosis of thyroid nodules

Introduction: Occurrence of thyroid nodules is a common clinical problem in Sri Lanka. Clinical assessment, biochemical investigations, ultrasonography, fine needle aspiration cytology (FNAC) and histology are used in the diagnosis.

Objectives: To determine the value of FNAC and ultrasonography (USS) to distinguish neoplastic nodules from non-neoplastic nodules of the thyroid.

Method: A retrospective cross sectional study involving 73 patients from Base Hospital Embilipitiya, during the period 2009 January to 2013 December was carried out.

Results: Study population was female predominant 70(95.9%) with the age ranging from 17-70 (mean 42.7). Sensitivity, specificity, positive predictive value, negative predictive values and accuracy for FNAC were 94.1%, 87.2%, 86.5%, 94.4%, and 90.4% respectively.  The corresponding values for ultrasonography were 64.7%, 69.2%, 64.7%, 69.2% and 67.1% respectively.

Conclusion: The findings of this study are in keeping with the other studies in Sri Lanka and the region. In addition, FNAC has a higher validity than USS in detection of thyroid neoplasms.