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Posters. P13 Cytohistological correlation in 212 FNAs of thyroid: analysis of discordant cases
Author(s) -
Dina R.
Publication year - 2003
Publication title -
cytopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 48
eISSN - 1365-2303
pISSN - 0956-5507
DOI - 10.1046/j.1365-2303.14.s1.1_29.x
Subject(s) - medicine , pathology , fine needle aspiration , thyroid , biopsy , thyroid carcinoma , false positive paradox , carcinoma , cytopathology , cytology , radiology , machine learning , computer science
Aim To detect major pitafalls in thyroid FNA and to confirm its in a clinical sensitivity and specificity. Methods A total of 9251 fine needle aspirations biopsy carried out at Bellaria Hospital in Bologna from 1991 to 2000 by a pathologist in the FNA Clinic or by a clinician under ultrasonic guidance using a small needle (25–27 G); at least two passes have been made for each nodule. The specimen was considered satisfactory if at least five groups of follicular cells with at least 10 cells each, were seen. The cytological results were tiered in a four categories classification: inadequate, negative, suspicious and positive. Cyto‐histological correlations were available in 212 cases: 127 benign lesions and 85 malignant lesions. An analysis of false positive cases and false negative cases was performed and discordant case reviewed according to the flowing criteria: architecture, cellularity, colloid, pseudoinclusions, nuclear groovings, chromatin pattern, nuclear membrane, cytoplasm, naked nuclei and lymphocytes. Results Diagnostic distribution in 9251 FNAs from the thyroid: 88.6% negatives, 2.8 suspicious, 2.4% positives and 6.2% inadequates. Specificity was 85.8% and sensitivity was 78.8%. Among the 18 false negative cases eight were papillary microcarcinomas, four papillary carcinomas, five follicular carcinoma and one a Hurtle cell carcinoma. Four false positive cases were found: three reported as papillary carcinomas and one as carcinoma NOS. Review of false positives showed that in three cases the colloid was fluid, in three cases nuclear grooving was rare or absent, in two cases degenerative vacuoles at MGG were interpreted as nuclear inclusions and in three cases benign naked nuclei were present in the background. Review of false negatives confirmed lack of malignant features in 13 (eight papillary microcarcinomas and five follicular carcinomas), five were interpretation errors (three papillary carcinomas, one follicular, one Hurtle cell). Conclusion FNAC of the thyroid is a sensitive and specific method of assessment for thyroid nodules but false negative and false positive cases do occur. Use of all and only few criteria enhances diagnostic accuracy.