Trends in Thyroid Aspiration Biopsy over a Decade: Analysis of over 1400 Cases
R Yu, J Cangiarella, A Simsir, J Waisman. New York University School of Medicine, New York, NY
Background: In 2006, the American Thyroid Association produced guidelines for fine needle aspiration biopsy (FNAB) as the procedure of choice in the evaluation of thyroid nodules. However, recent published studies of thyroid FNAB by palpation or with ultrasound guidance show wide variability in non-diagnostic specimens and in atypical or indeterminate diagnoses, which often lead to surgery. We reviewed our experience with thyroid FNAB over a decade to assess trends in our practice.
Design: Annual (1995, 2000, and 2005) thyroid FNABs performed over eleven years at the NYU School of Medicine were reviewed and compared. The method of aspiration (by palpation or by ultrasound guidance) and the physician performing the aspiration (pathologist, radiologist, endocrinologist, or surgeon) were recorded. Diagnoses were classified as non-diagnostic, benign, atypical/suspicious (including those with mention of follicular and Hrthle cell neoplasms), or malignant. The majority of our diagnoses were made from direct smears.
table 1*In 1995, 52% of thyroid FNABs had on-site assessment by a pathologist compared to 69% in 2005.
|1995 (n=79)||2000 (n=480)||2005 (n=857)|
|METHOD OF ASPIRATION*|
|Palpation||67 (85%)||134 (28%)||59 (7%)|
|Ultrasound Guidance||12 (15%)||346 (72%)||798 (93%)|
|Benign||61 (77.2%)||415 (86.5%)||781 (91.1%)|
|Malignant||5 (6.3%)||9 (1.9%)||22 (2.6%)|
|Non-diagnostic||6 (7.6%)||12 (2.5%)||17 (2.0%)|
|Atypical/Suspicious||7 (8.9%)||44 (9.2%)||37 (4.3%)|
Conclusions: 1) From 1995 to 2005 there was a ten-fold increase in the total number of thyroid FNABs. During this period, there was an increase in thyroid FNAB with ultrasound guidance from 15% to 93% and a corresponding decline by palpation. 2) There was a progressive increase in the number of thyroid FNABs over eleven years, but the majority were benign accounting for the increase in the benign category from 77% to 91%. 3) The number of malignant diagnoses was low and remained stable; ultrasound guidance did not adversely affect the rate of malignancy. 4) Liquid based preparations were not necessary to achieve these results. 5) There was a decrease in the non-diagnostic category and the atypical category presumably due to more experience with the performance and interpretation of thyroid FNABs, increased on-site assessment, and increased ultrasound guidance.
Monday, March 9, 2009 9:30 AM
Poster Session I Stowell-Orbison/Autopsy Award # 71, Monday Morning