[420] Restrospective Evaluation of Instituted Standard Adequacy Criteria for On-Site Adequacy Assessment of Thyroid Fine Needle Aspiration (FNA)

X Jing, E Wey, CW Michael. University of Michigan, Ann Arbor, MI

Background: Criteria for specimen adequacy of thyroid FNAs on permanent smears are still controversial. To our knowledge, there are no criteria set forth for on site assessment of adequacy performed on Diff-Quick (preliminary smears) which results in lack of uniformity among different pathologists. In 2006 we implemented the requirement of a minimum of 6 clusters, each consisting of 10 follicular cells or more as standard criteria for on site adequacy.
Design: A total of 1031 thyroid FNA performed between 07/2006 and 03/2009 with on site assessment performed based on the standard criteria were reviewed. Agreement between on site and final assessment of specimen adequacy, Distribution of cytologic diagnoses were evaluated. Further, cyto-histologic concordance (neoplasia vs. nonneoplasia) was assessed on 221 cases with surgical follow-up.
Results:

Agreement on specimen adequacy between on site and final assessment

Final	On site-adequate N (%)	On site-inadequate N (%)	Totals N (%)
Adequate	851 (99.8)	70 (39.3)	921 (89.3)
Inadequate	2 (0.2)	108 (60.7)	110 (10.7)
Totals	853 (100)	178 (100)	1031 (100)

Distribution of cytologic diagnosis and cyto-histologic concordance

Cytologic diagnosis	N	Surgical follow-up N (%)	Concordant case N (%)
Adequate	921	221 (24.0)	139 (62.9)
–Nonneoplasia	722	66 (9.1)	62 (93.9)
––NH	638	62	58 (93.5)
––LT	84	4	4 (100)
–FL/HL	116	87 (75.0)	21 (24.1)∗
–Neoplasia	83	68 (81.9)	56 (82.3)
––FN/HN	29	19 (65.5)	14 (73.7)
––PTC	46	41 (89.1)	34 (82.9)
––others	8	8 (100)	8 (100)
Inadequate	110	11 (10)	-

NH: nodular hyperplasia; LT: lymphocytic thyroiditis; FL/HL: follicular/Hurthle cell lesions of undetermined significance; FN/HN: follicular/Hurthle cell neoplasm; PTC: papillary carcinoma; Others: medullary/anaplastic/squamous cell carcinoma+ lymphoma + parathyroid adenom; * neoplasia on surgical follow-up.


Conclusions: Implementing standard criteria for on site adequacy assessment of specimen adequacy resulted in: 1) 93.0% level of agreement on specimen adequacy between on site and final assessment. 2) Nondiagnostic rate of 10.7%, compatible with published literature. 3) Cyto-histologic concordant rate of 93.9% for non-neoplastic and 82.3% for neoplastic lesions, compatible with published literature. 4) Provided consistency among cytopathologist when compared with previously published data. 5) More effective communication and high satisfaction from utilizers of our on site services.
Category: Cytopathology

Tuesday, March 23, 2010 9:30 AM

Poster Session III # 92, Tuesday Morning