Radhika H. Pillai1 , Jeena V. Chimmen2 , Aswathi R.3
BACKGROUND Fine Needle Aspiration Cytology (FNAC) plays a pivotal role in the diagnosis of thyroid nodules. The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) has improved the quality of cytology reporting. Bethesda category III or Atypia of Undetermined Significance / Follicular Lesion of Undetermined Significance (AUS / FLUS) has been a challenge to pathologists and our objective is to study the significance of Bethesda classification and assess the malignancy risk in AUS / FLUS to plan subsequent management strategy. METHODS The study comprised of 133 patients who underwent fine needle aspiration followed by surgery from January 2012 to June 2013 in our institution. Cytology smears were evaluated and reported according to Bethesda system of reporting thyroid cytopathology. Fine needle aspiration cytology diagnosis was compared with the histopathology reports. RESULTS On evaluating cytopathology reporting as per Bethesda system, highest number of cases was in the “suspicious for follicular neoplasm / follicular neoplasm category”. Incidence of AUS / FLUS was 17.3 %, and the malignancy rate in this category was 60 % which is the highest reported, compared to other similar studies. The most common malignancy was papillary carcinoma. CONCLUSIONS Fine Needle Aspiration Cytology (FNAC) is still the most cost effective minimal invasive technique in the diagnosis of thyroid neoplasm. The higher malignancy rate in AUS / FLUS in the present study warrants early surgical intervention as the appropriate management, than the current strategy of “repeat FNAC” in this category. The current study also showed definite correlation between histopathology and FNAC in the diagnosis of thyroid malignancy.
