[457] Liquid-Based Cytology Improves the Identification of Malignant Tumors in Thyroid Fine-Needle Biopsies

ED Rossi, A Santoro, VG Vellone, S Moncelsi, G Zannoni, G Fadda. Catholic University, Rome, Italy; University of Foggia, Foggia, Italy

Background: Fine-needle aspiration cytology (FNAC) is the most important tool for correctly diagnosing thyroid malignant tumors. The introduction of liquid-based cytology (LBC) has allowed the standardization of the technical processing of the aspirations and the better identification of the malignant features of the follicular cells. The aim of this study is to assess the efficacy of the LBC in identifying malignant neoplasms in suspicious lesions sampled by FNA.
Design: In 2008 2,622 thyroid biopsies have been carried out in the Division of Pathology of the Catholic University of Rome under sonographic guidance.All biopsies were processed according to the Thin Prep 2000 method (Hologic,Marlborough,MA). Among them 333 (12.7%) were classified as follicular neoplasm (Thy 3 according to the British Thyroid Association, BTA) and 85 (3.2%) as suspicious for malignant tumor (Thy 4 according to the BTA). The overall rate of suspicious lesions accounted for 15.9%. Among these patients 199 (47.6%) underwent surgery: 136 diagnosed as Thy 3 (40.4%) and 63 diagnosed as Thy 4 (74.1%).
Results: The overall rate of malignant occurrence in suspicious thyroid lesions was 19.6%. In Thy 3 the malignant neoplasms represented 26.4% (36 out of 136 patients addressed to surgery) whereas the Thy 4 malignancy rate was 73% (46 out of 63 operated patients). The comparison with previous periods (2004 with LBC only, 2001-2002 with LBC plus conventional smears, CS, and 1995 with only CS) shows a statistically significant increase of both malignancy rates. In fact the Thy 3 category malignancy occurrence was 14.4% in 2004, 11.5% in 2001-2002 and 2.1% in 1995 whereas the same rate of malignancy in Thy 4 lesions was 53.4% in 2004, 77.5% in 2001-2002 and 46.1% in 1995.The PPV and NPV were respectively 73 and 73.5%
Conclusions: The adoption of the LBC cytology may help in identifying more correctly than CS the cases showing malignant features on thyroid fine-needle biopsies. Rossi ED et al.Diagnostic Efficacy of Conventional as Compared to Liquid-Based Cytology in Thyroid Lesions. Acta Cytol.(in press)
Category: Cytopathology

Tuesday, March 23, 2010 9:30 AM

Poster Session III # 97, Tuesday Morning

 

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