Lubin DJ, Griffith CC, Buonocore DJ, Wei XJ, Lin O. Putting morphology to the test: An established classification scheme reliably stratifies salivary gland cytology by risk of malignancy with substantial interobserver agreement.
Cancer Cytopathol 2020;
129:291-303. [PMID:
33136345 DOI:
10.1002/cncy.22382]
[Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 09/23/2020] [Accepted: 09/28/2020] [Indexed: 12/11/2022]
Abstract
BACKGROUND
The Milan System for Reporting Salivary Gland Cytopathology describes several salivary gland fine-needle aspiration cytology (SGFNAC) morphologies developed by Griffith et al. Basaloid neoplasms are pleomorphic (PB) or monomorphic with fibrillary (MBFib), hyaline (MBHy), or other (MBOther) matrix. Oncocytoid neoplasms can be pleomorphic (PO), demonstrate granular and/or vacuolated cytoplasm (OGV), or be monomorphic with mucinous (MOMuc), cystic (MOCyst), or other (MOOther) background. In the current study, the authors explore interobserver agreement (IOA) and risk of malignancy (ROM) for these subcategories.
METHODS
The study included 169 SGFNAC cases with surgical follow-up. Four reviewers categorized these cases using the criteria of Griffith et al. with consensus determined by majority. For all morphologic categories, IOA (using the Fleiss kappa) and ROM were calculated.
RESULTS
ROMs for basaloid categories were: PB: 100% (1 of 1 case); MBHy: 71.4% (5 of 7 cases); MBFib: 50.0% (3 of 6 cases); and MBOther: 47.4% (9 of 19 cases). ROMs for oncocytoid neoplasms were: OGV: 100% (10 of 10 cases); MOMuc: 92.3% (12 of 13 cases); PO: 88.9% (8 of 9 cases); MOOther: 33.3% (5 of 15 cases); and MOCyst: 0 (0 of 1 case). The system demonstrated substantial agreement overall (κ = 0.69). For basaloid neoplasms, the IOA results were: MBHy: κ = 0.59; MBFib: κ = 0.41; MBOther: κ = 0.41; and PB: κ = 0.11. For oncocytoid neoplasms, the IOA results were: MOMuc: κ = 0.88; OGV: κ = 0.67; PO: κ = 0.63; MOOther: κ = 0.57; and MOCyst: κ = 0.18.
CONCLUSIONS
The SGFNAC scheme proposed by Griffith et al. and incorporated into the Milan System for Reporting Salivary Gland Cytopathology demonstrated substantial agreement overall, with particularly high agreement for the MOMuc, OGV, PO, and MBHy categories. The PB and MOCyst categories demonstrated slight agreement and may be improved by revised criteria. The PB, PO, MOMuc, and OGV categories demonstrated high ROM, and the latter 2 categories might best be classified as suspicious for malignancy.
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