He S R, Cui D, Gong H, Zhu Y P, Chen L, Hu S T, Liu D G
Department of Pathology, Beijing Hospital, Beijing 100730, China.
Zhonghua Bing Li Xue Za Zhi. 2017 Jun 8;46(6):393-399. doi: 10.3760/cma.j.issn.0529-5807.2017.06.006.
To study the cytomorphologic features and determine whether pancreatic neuroendocrine tumors (PanNET) sampled by fine-needle aspiration (FNA) can be accurately graded based on the Ki-67 index when compared to surgical samples. Corresponding intraoperative (19 cases) or endoscopic ultrasound-guided (3 cases) FNA cytology and surgical tissue specimens were obtained from 22 tumors, which were reviewed and stained for Ki-67 proliferation marker. The cytological samples included more than 200 tumor cells. Samples were graded by scoring the Ki-67 positive index in accordance with the 2010 WHO criteria. The grading scores assigned to the FNA cytology samples were compared with the scores assigned to the corresponding histological samples. Concordance was achieved by using 5% (instead of 2%) as a cut-off value for defining G2 tumors. One cytological sample included less than 500 tumor cells was excluded in the concordance calculation. The cytological smears consisted of uniform, monotonous and isolated cells, loose cellular aggregates and rosette-like formations. Some tumor cells clustered around segments of capillaries. The cells demonstrated distinct cytoplasmic and nuclear features. Mitoses and necrosis were rarely seen. When traditional 2% Ki-67 index cut-off value were used to classify G2 tumors, the majority (86.4%, =0.812, <0.01) of FNA cytology samples and corresponding surgical tissue specimens demonstrated concordance. When a 5% cut-off value was adopted, the concordance rate was 95.5% (21/22, =1.000, <0.01). Similar concordance rates between the cytological and histological grades were achieved with threshold value of cytological assessment material set at more than 500 or 200 cells. The cytological Ki-67 index in adequate material (>200 tumor cells) is useful in grading pancreatic neuroendocrine tumors, and a cut-off value of 5% showed better predictive value compared with that of 2%. Accurate grading of PanNET is critical for predicting tumor biology, patient prognosis, and making informed decisions regarding patient management and treatment.
研究胰腺神经内分泌肿瘤（PanNET）细针穿刺活检（FNA）样本的细胞形态学特征，并确定与手术样本相比，能否基于Ki-67指数对其进行准确分级。从22个肿瘤中获取了相应的术中（19例）或超声内镜引导下（3例）FNA细胞学样本及手术组织标本，对其进行复查并检测Ki-67增殖标志物。细胞学样本包含200多个肿瘤细胞。根据2010年世界卫生组织标准，通过对Ki-67阳性指数进行评分对样本进行分级。将FNA细胞学样本的分级分数与相应组织学样本的分级分数进行比较。以5%（而非2%）作为界定G2肿瘤的临界值可实现一致性。在一致性计算中排除了一个肿瘤细胞少于500个的细胞学样本。细胞学涂片由均匀、单一且孤立的细胞、松散的细胞聚集体和玫瑰花结样结构组成。一些肿瘤细胞围绕毛细血管片段聚集。细胞呈现出明显的细胞质和细胞核特征。很少见到有丝分裂和坏死。当使用传统的2% Ki-67指数临界值对G2肿瘤进行分类时，大多数（86.4%，=0.812，<0.01）FNA细胞学样本与相应手术组织标本显示出一致性。当采用5%临界值时，一致性率为95.5%（21/22，=1.000，<0.01）。当细胞学评估材料的阈值设定为超过500或200个细胞时，细胞学和组织学分级之间也获得了相似的一致性率。足够样本量（>200个肿瘤细胞）中的细胞学Ki-67指数有助于对胰腺神经内分泌肿瘤进行分级，与2%相比，5%的临界值显示出更好的预测价值。准确分级PanNET对于预测肿瘤生物学行为、患者预后以及就患者管理和治疗做出明智决策至关重要。
