Thyroid follicular cell tumors: cytohistological comparisons in the context of the new international classification

• Published in: Arkhiv patologii Vol. 82; no. 1; p. 15
• Main Authors: Abrosimov, A Yu, Abdulkhabirova, F M, Shifman, B M
• Format: Journal Article
• Language: Russian
• Published: Russia (Federation) 2020
• Subjects: Adenocarcinoma, Follicular; Biopsy, Fine-Needle; Humans; Retrospective Studies; Russia; Thyroid Epithelial Cells; Thyroid Neoplasms; Russia; morphological diagnosis; new histological classification; thyroid; follicular neoplasms
• ISSN: 0004-1955
• DOI: 10.17116/patol20208201115

To carry out a correlation retrospective analysis of the histological and cytological findings of follicular cell neoplasms over a two-year period after the publication of the new WHO classification of thyroid tumors (2017), which identifies a category of follicular tumors of uncertain malignant potential (T-UMP).
The investigators of the Clinic, National Medical Research Center for Endocrinology, Ministry of Health of Russia, made a cytohistological comparison of morphological findings, by using the material of surgically removed follicular cell neoplasms.
The investigation showed the lack of unreasonably common usage of the histological classification category of T-UMP (3.08%). Non-invasive follicular neoplasm with papillary-like nuclei predominantly diagnosed in the T-UMP category was more frequently (83.3) assigned to Diagnostic Category IV of the 2017 Bethesda system for the cytological diagnosis of thyroid tumors. Cytology showed the highest (98.1%) sensitivity, including classic (97.8%), encapsulated (100%), and follicular (97.7%) options in diagnosing papillary cancer, being substantially inferior in diagnosing follicular and Hürthle cell neoplasms, in which diagnostic category IV category was more frequently established for adenomas (81.4%) and carcinomas (69.5%).
The morphological differential diagnosis of follicular cell neoplasms seems to be a relevant problem.