A comparative study of free-hand fine needle aspiration cytology and ultrasound guided fi ne needle aspiration cytology in the diagnosis of thyroid swellings at BP Koirala Institute of Health Sciences- a tertiary care centre in Nepal

Abstract

Background: Thyroid lesions are commonly encountered in clinical practice and it  is mandatory to know and record the nature of pathology prior to definitive therapy.  Fine needle aspiration cytology (FNAC) is a time tested, cheap, reliable and safe  method to establish a cytological diagnosis of the nature of the disease. Ultrasound  guided FNAC has the potential to reduce inadequacy rates and is regarded as  the optimal cytological method for diagnosis.

Objective: To compare the results  of free-hand and ultrasound-guided FNAC of thyroid swellings and to find out  the diagnostic reliability of free-hand FNAC and ultrasound-guided FNAC using  histological diagnosis as the gold standard.

Methods: Fifty-five patients with thyroid  swelling who were subjected to free-hand and ultrasound-guided FNACs and who  subsequently underwent surgery over one year were studied.

Results: Ultrasound  guided FNAC results revealed 72.75 % benign lesions and 25.45 % of malignant  lesions, and free hand FNAC revealed 52.73 % benign and 16.36% malignant cases.  A 14.55 % inadequacy rate was seen in the free hand group. Histological gold  standard diagnosis comprised of 60 % benign and 40 % malignant cases. Sensitivity  and specificity of free-hand and ultrasound guided FNAC in diagnosing malignancy  of the thyroid were 56.25% and 100%; and 63.64% and 96.97% respectively. 

Conclusion: Free hand FNAC of thyroid swellings is more convenient and cost  effective as compared to ultrasound guided FNAC. However, the diagnostic yield  in ultrasound guided FNAC is significantly more in terms of accuracy especially in  cystic and tiny lesions.

Health Renaissance 2014;12(2): pp. 78-86