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The influence of the noninvasive follicular thyroid neoplasm with papillary‐like nuclear features (NIFTP) resection diagnosis on the false‐positive thyroid cytology rate relates to quality assurance thresholds and the application of NIFTP criteria
Author(s) -
Ohori N. Paul,
Wolfe Jenna,
Carty Sally E.,
Yip Linwah,
LeBeau Shane O.,
Berg Aaron N.,
Schoedel Karen E.,
Nikiforov Yuri E.,
Seethala Raja R.
Publication year - 2017
Publication title -
cancer cytopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.29
H-Index - 57
eISSN - 1934-6638
pISSN - 1934-662X
DOI - 10.1002/cncy.21892
Subject(s) - medicine , thyroid neoplasm , malignancy , radiology , thyroid carcinoma , cytology , medical diagnosis , thyroid , pathology
BACKGROUND Noninvasive follicular thyroid neoplasm with papillary‐like nuclear features (NIFTP) is a newly defined entity and recent studies have suggested a decrease of a few percentage points in the rate of malignancy (ROM) for the positive‐for‐malignancy (PFM) cytology category as a result of NIFTP implementation. However, the distinction between a diagnosis of PFM and one of suspicious for malignancy (SFM) may depend on a variety of factors. In the current study, the authors investigated the ROM for the PFM and SFM diagnoses before and after histologic NIFTP reclassification. METHODS Cytology cases with PFM and SFM diagnoses and subsequent surgical resection specimens were searched in the files of the study institution from September 2008 to September 2016. The surgical pathology cases of noninvasive encapsulated follicular variant of papillary thyroid carcinoma were reexamined to determine whether they qualified for NIFTP. The distinct ROMs for the PFM and SFM cases were calculated accordingly. RESULTS The authors' search identified 338 cases of PFM and 139 cases of SFM with a resection outcome. Before NIFTP reclassification, the PFM cases had a ROM of 99.4%; after NIFTP reclassification, the ROM was 99.1% ( P = .6861). The ROM of the SFM cases decreased from 75.5% to 66.9% with NIFTP reclassification ( P = .1402). One case in the PFM group and 6 cases in the SFM group could not be verified due to insufficient sampling. CONCLUSIONS In the current large series, NIFTP reclassification did not appear to significantly alter the high ROM for the PFM diagnosis. The authors attribute this finding to a strict quality assurance policy, an emphasis on key cytologic criteria, and systematic application of the NIFTP criteria to follicular‐patterned lesions. Cancer Cytopathol 2017;125:692‐700. © 2017 American Cancer Society .