Endocr Pract. 2019 Jul;25(7):642-647. doi: 10.4158/EP-2018-0423. Epub 2019 Mar 13.
Noninvasive encapsulated follicular variant of papillary thyroid carcinoma (EFVPTC) was recently reclassified as noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). We aimed to compare the risk of malignancy (ROM) of the Bethesda System for Reporting Thyroid Cytopathology (BSRTC) on fine-needle aspiration cytology (FNAC), before and after the reclassification, in a large cohort of patients. We analyzed 5,625 consecutive FNAC samples performed in 2012-2014 and selected category III (atypia of undetermined significance [AUS]/follicular lesion of undetermined significance [FLUS]), IV (follicular neoplasm [FN]/suspicious for a follicular neoplasm [SFN]), V (suspicious for malignancy [SFM]), and VI (malignant) of the BSRTC. We reviewed the histology of operated patients and compared ROM before and after the introduction of the NIFTP category. A total of 772 patients were identified and 45% underwent surgery (n = 348). There were 180 cases of AUS/FLUS (10 NIFTP), 114 cases of FN/SFN (2 NIFTP), 29 cases of SFM (3 NIFTP), and 25 cases of BSRTC VI (no NIFTP). Exclusion of NIFTP from malignant lesions resulted in a relative and absolute decrease in the ROM in AUS/FLUS (15.2% and 5.5%, respectively), FN/SFN (7.6% and 1.8%, respectively) and SFM (14.2% and 10.3%, respectively) categories. Among the NIFTP patients, 93% underwent total thyroidectomy and 20% received radioiodine. Reclassification of noninvasive EFVPTC as NIFTP resulted in a decrease in overall ROM, and the BSRTC categories most affected were III and V. = atypia of undetermined significance; = Bethesda System for Reporting Thyroid Cytopathology; = encapsulated follicular variant of papillary thyroid carcinoma; = follicular lesion of undetermined significance; = follicular neoplasm; = fine-needle aspiration cytology; = follicular variant of papillary thyroid carcinoma; = noninvasive follicular thyroid neoplasm with papillary-like nuclear features; = papillary thyroid carcinoma; = risk of malignancy; = suspicious for malignancy; = suspicious for a follicular neoplasm.
非侵袭性包裹滤泡型甲状腺乳头状癌（EFVPTC）最近被重新分类为非侵袭性滤泡性甲状腺肿瘤，具有乳头状核特征（NIFTP）。我们旨在比较在大型患者队列中，贝塞斯达甲状腺细胞学报告系统（BSRTC）对细针抽吸细胞学（FNAC）的风险恶性度（ROM）在重新分类前后的变化。我们分析了 2012-2014 年连续进行的 5625 例 FNAC 样本，选择了 BSRTC 的第 III 类（意义不明的不典型性[AUS]/滤泡性病变意义不明[FLUS]）、第 IV 类（滤泡性肿瘤[FN]/可疑滤泡性肿瘤[SFN]）、第 V 类（可疑恶性[SFM]）和第 VI 类（恶性）。我们回顾了手术患者的组织学，并比较了引入 NIFTP 类别前后的 ROM。共确定了 772 例患者，其中 45%（n=348）接受了手术。AUS/FLUS 有 180 例（10 例为 NIFTP），FN/SFN 有 114 例（2 例为 NIFTP），SFM 有 29 例（3 例为 NIFTP），BSRTC VI 有 25 例（无 NIFTP）。将 NIFTP 从恶性病变中排除后，AUS/FLUS（分别为 15.2%和 5.5%）、FN/SFN（分别为 7.6%和 1.8%）和 SFM（分别为 14.2%和 10.3%）的 ROM 出现相对和绝对下降。在 NIFTP 患者中，93%接受了全甲状腺切除术，20%接受了放射性碘治疗。将非侵袭性 EFVPTC 重新分类为 NIFTP 导致整体 ROM 降低，受影响最大的 BSRTC 类别是 III 类和 V 类。
