Legesse Teklu, Parker Lynnette, Heath Jonathon, Staats Paul N
Department of Pathology, University of Maryland School of Medicine, Baltimore, Maryland.
Department of Pathology, University of Maryland School of Medicine, Baltimore, Maryland.
J Am Soc Cytopathol. 2019 Jan-Feb;8(1):11-17. doi: 10.1016/j.jasc.2018.07.004. Epub 2018 Jul 24.
An international panel recently recommended reclassification of non-invasive follicular variant of papillary thyroid carcinoma (PTC) to non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). NIFTPs have little or no risk of recurrence and can be treated with lobectomy alone. Preoperative distinction of NIFTP from PTC will help avoid overtreatment.
All thyroid tumors with a histologic diagnosis of PTC and preceding diagnostic cytology (n = 299) over a 5-year period were identified. Cases meeting criteria for NIFTP were reclassified as such. All NIFTP cases with available cytology (n = 6) and a similar number of randomly selected invasive follicular variant of papillary thyroid carcinoma (IFVPTC; n = 9) and classic PTC (cPTC, n = 11) were evaluated for 18 cytologic features.
A total of 35 (12%) lesions were reclassified as NIFTP, 194 (65%) were cPTC, and 70 (23%) were IFVPTC. The NIFTPs had a preceding cytologic interpretation of benign (31%), atypia of undetermined significance (34%), follicular neoplasm (9%), suspicious for malignancy (12%), or malignant (14%). Cytologically, NIFTP was distinguished from cPTC by absence of any architectural features in all 6 cases, and by absence of pseudoinclusions (P < 0.001) and multinucleated giant cells (P = 0.027) in nearly all. Nuclear pseudoinclusions (P = 0.001), marginal micronucleoli (P = 0.018), irregular branching sheets (P = 0.025), and linear arrangement (P = 0.025) favored IFVPTC over NIFTP.
NIFTPs were originally assigned to a variety of cytologic categories. There are several cytologic differences between NIFTP and cPTC or IFVPTC. Our findings support restricting the definitive diagnosis of PTC to cases with architectural features of PTC and/or intranuclear pseudoinclusions.
一个国际专家小组最近建议将甲状腺乳头状癌（PTC）的非侵袭性滤泡变体重新分类为具有乳头状核特征的非侵袭性滤泡性甲状腺肿瘤（NIFTP）。NIFTP几乎没有或没有复发风险，仅行甲状腺叶切除术即可治疗。术前将NIFTP与PTC区分开来将有助于避免过度治疗。
确定了5年内所有经组织学诊断为PTC且有术前诊断性细胞学检查的甲状腺肿瘤（n = 299）。符合NIFTP标准的病例进行重新分类。对所有有可用细胞学检查的NIFTP病例（n = 6）以及数量相似的随机选择的甲状腺乳头状癌侵袭性滤泡变体（IFVPTC；n = 9）和经典PTC（cPTC，n = 11）病例评估18种细胞学特征。
共有35例（12%）病变重新分类为NIFTP，194例（65%）为cPTC，70例（23%）为IFVPTC。NIFTP术前细胞学诊断为良性的占31%，意义不明确的非典型性占34%，滤泡性肿瘤占9%，可疑恶性占12%以及恶性占14%。在细胞学上，6例NIFTP均无任何结构特征，几乎所有病例均无假包涵体（P < 0.001）和多核巨细胞（P = 0.），以此与cPTC区分。核假包涵体（P = 0.001）、边缘微核仁（P = 0.018）、不规则分支片层（P = 0.025）和线性排列（P = 0.025）表明IFVPTC与NIFTP相比更具这些特征。
NIFTP最初被归为多种细胞学类别。NIFTP与cPTC或IFVPTC之间存在一些细胞学差异。我们的研究结果支持将PTC的明确诊断限制在具有PTC结构特征和/或核内假包涵体的病例中。
