透明细胞乳头状肾细胞癌的影像学表现

目的探讨透明细胞乳头状肾细胞癌(CCPRCC)的影像学表现。方法分析15例CCPRCC患者CT及MRI影像特征,采用独立样本t检验比较肿瘤与肾皮质之间平扫CT值、ADC值差异。结果15例均为单发,边界清晰,大小为(3.1±1.9)cm。13例为实性肿瘤,其中11例伴囊变,2例为囊性肿瘤。4例CT平扫呈等或稍低密度,4例呈稍高密度;6例密度不均匀,1例伴细条状钙化;8例CT值为(38.4±10.6)HU,与肾皮质比较差异无统计学意义(P>0.05)。8例MRI平扫T1WI呈稍低或低信号,3例伴发结节状、灶状高信号;8例T2WI以混杂高信号为主,5例边缘见包膜;7例DWI呈稍高信号;9例肿瘤ADC值(2.22±0.30)×10-3 mm2/s高于肾皮质,两者差异具有统计学意义(P<0.05)。增强扫描13例实性肿瘤中9例呈“快进快出”强化,4例呈持续或渐进性强化;2例囊性肿瘤增强扫描呈囊壁及中心分隔强化。结论CCPRCC好发于中老年人,肿瘤易发生囊变,出血、钙化少见,弥散受限不明显,增强扫描以“快进快出”强化为主,确诊仍需依靠组织病理学。     

Differentiation between Clear Cell Sarcoma of the Kidney and Wilms' Tumor with CT

ObjectiveClear cell sarcoma of the kidney (CCSK) is the second-most common but extremely rare primary renal malignancy in children after Wilms'' tumor. The aims of this study were to evaluate the imaging features that could distinguish between CCSK and Wilms'' tumor and to assess the features with diagnostic value for identifying CCSK.Materials and MethodsWe reviewed the initial contrast-enhanced abdominal-pelvic CT scans of children with CCSK and Wilms'' tumor between 2010 to 2019. Fifty-eight children (32 males and 26 females; age, 0.3–10 years), 7 with CCSK, and 51 with Wilms'' tumor, were included. The maximum tumor diameter, presence of engorged perinephric vessels, maximum density of the tumor (Tmax) of the enhancing solid portion, paraspinal muscle, contralateral renal vein density, and density ratios (Tmax/muscle and Tmax/vein) were analyzed on the renal parenchymal phase of contrast-enhanced CT. Fisher''s exact tests and Mann-Whitney U tests were conducted to analyze the categorical and continuous variables, respectively. Logistic regression and receiver operating characteristic curve analyses were also performed.ResultsThe age, sex, and tumor diameter did not differ between the two groups. Engorged perinephric vessels were more common in patients in the CCSK group (71% [5/7] vs. 16% [8/51], p = 0.005). Tmax (median, 148.0 vs. 111.0 Hounsfield unit, p = 0.004), Tmax/muscle (median, 2.64 vs. 1.67, p = 0.002), and Tmax/vein (median, 0.94 vs. 0.59, p = 0.002) were higher in the CCSK compared to the Wilms'' group. Multiple logistic regression revealed that engorged vessels (odds ratio 13.615; 95% confidence interval [CI], 1.770–104.730) and Tmax/muscle (odds ratio 5.881; 95% CI, 1.337–25.871) were significant predictors of CCSK. The cutoff values of Tmax/muscle (86% sensitivity, 77% specificity) and Tmax/vein (71% sensitivity, 86% specificity) for the diagnosis of CCSK were 1.97 and 0.76, respectively.ConclusionPerinephric vessel engorgement and greater tumor enhancement (Tmax/muscle > 1.97 or Tmax/vein > 0.76) are helpful for differentiating between CCSK and Wilms'' tumor in children aged below 10 years.     

A rare case of clear cell sarcoma with 4 types of EWSR1-ATF1 fusions detected not in primary site but in metastatic site

Clear cell sarcoma is a unique tumor which has EWSR1-ATF1 or EWSR1-CREB1 fusion. Several patterns of EWSR1-ATF1 fusion are observed in clear cell sarcoma. Since type 5–7 fusions were reported recently, they are classified as type 1–7. We examined EWSR1-ATF1 and EWSR1-CREB1 fusions in a single case of clear cell sarcoma with lung metastasis in a 36-year-old Japanese man. As a result, we found only type 1 EWSR1-ATF1 fusion in the primary site, but 4 types of EWS-ATF1 fusion (type 1, 2, 5, 6) were detected in the metastatic site. These 4 types of fusion were completely identical to the recent report, but the case had the same fusion patterns in both primary and metastatic sites. In our case, increased splicing activity in the EWSR1-ATF1 fusion might be acquired at the metastatic site. There is another possibility that metastasis might develop through the increased splicing activity in the fusion.     

Clear aligner orthodontic therapy of rotated mandibular round-shaped teeth: A finite element study

Objective:To evaluate, using the finite element method, the orthodontic rotational movement of a lower second premolar obtained with clear aligners, analyzing different staging and attachment configurations.Materials and Methods:A CAD model including a complete lower dental arch (with element 4.5 mesially rotated 30°) and the corresponding periodontal ligaments, attachments, and aligner was designed and imported to finite element software. Starting from the CAD model, six projects were created to simulate the following therapeutic combinations for correcting element 4.5 position: (1) without attachments, (2) single attachment placed on the buccal surface of element 4.5, (3) three attachments placed on the buccal surfaces of teeth 4.4 to 4.6. For each project, both 1.2° and 3° of aligner activation were considered.Results:All the analyzed configurations revealed a clockwise rotation movement of element 4.5 on the horizontal plane. Models with attachments showed a greater tooth displacement pattern than models without attachments. Simulations with attachments and 3° of aligner activation exhibited the best performance concerning tooth movement but registered high stresses in the periodontal ligaments, far from the ideal stress levels able to produce tooth rotational movement.Conclusions:The model with a single attachment and 1.2° of aligner activation was the most efficient, followed by the three attachment model with the same degree of activation. Aligner activation should not exceed 1.2° to achieve better control of movement and reasonable stress in periodontal structures.     

肺透明细胞肿瘤2例临床病理观察

目的探讨肺透明细胞肿瘤的临床病理特征、鉴别诊断及预后。方法回顾性分析2例肺透明细胞肿瘤的临床病理特点,并复习相关文献。结果2例肺透明细胞肿瘤均为女性,年龄分别为67岁和53岁,因查体胸透和体检时偶然发现,无临床症状。肿瘤均靠近于肺周边部,肿瘤直径3.5 cm和1.5 cm,均在胸腔镜下做肺叶切除术及纵隔淋巴结清扫术。大体为界限清楚的结节,切面灰红实性,质地偏软,其内可见小的囊腔样结构。镜下见多角形的肿瘤细胞呈实性、片状或条索状排列,肿瘤细胞间可见较多薄壁血管及玻璃样变性的小血管。核圆形或卵圆形,形态温和,胞质丰富、透明,部分肿瘤细胞胞质嗜酸性,细胞形态较一致,未见核分裂象和坏死。免疫组化染色肿瘤细胞HMB45、Melan A、CD68(+),CK、CK7、EMA、TTF-1、S-100、NSE、Cg A、Syn、CD56、PAX8和TFE3(-)。Ki-67增殖指数均很低。肿瘤细胞富于糖原,组织化学染色PAS(+),消化后PAS(-)。结论肺透明细胞肿瘤是一种少见良性肿瘤,预后良好,易与其他透明细胞癌及转移性肾透明细胞癌相混淆,熟悉其临床和病理特征可以避免误诊。     

Cystic renal cell carcinoma carries an excellent prognosis regardless of tumor size

IntroductionCystic renal cell carcinoma (cystic RCC) is thought to carry an improved prognosis relative to clear cell RCC (CCRCC); however, this is based on small case series. We used a population-based tumor registry to compare clinicopathologic features and cancer-specific mortality (CSM) of cystic RCC with those of CCRCC.Materials and methodsThe Surveillance, Epidemiology, and End Results database was queried for all patients diagnosed and treated for cystic RCC and CCRCC between 2001 and 2010. Clinical and pathologic factors were compared using t tests and chi-square tests as appropriate. Kaplan-Meier survival analysis compared CSM differences between cystic RCC and CCRCC.ResultsA total of 678 patients with cystic RCC and 46,677 with CCRCC were identified. The mean follow-up duration was 52 and 40 months, respectively. When compared with CCRCC patients, those with cystic RCC were younger (mean age 58 vs. 61 y, P <0.001), more commonly black (22% vs. 9%, P<0.001), and female (45% vs. 41%, P = 0.02). Cystic RCCs were more commonly T1a tumors (66% vs. 55%, P<0.001), well differentiated (33% vs. 16%, P<0.001), and smaller (mean size = 3.8 vs. 4.5 cm, P<0.001). Cystic RCC was associated with a reduction in CSM when compared with CCRCC (P = 0.002). In a subset analysis, this reduction in CSM was seen only for those with T1b/T2 tumors (P = 0.01) but not for those with T1a RCCs lesions (P = 0.31).ConclusionsWe report the largest series of cystic RCC and corroborate the findings of improved CSM when compared with CCRCC for larger tumors; however, no difference was noted in smaller tumors, suggesting that tumor biology becomes more relevant to prognosis with increasing size. These data may suggest a role for active surveillance in appropriately selected patients with small, cystic renal masses.     

无托槽隐形矫技术中附件粘接的临床体会

目的：介绍无托槽隐形矫治技术中常用的辅助装置—＂附件＂的临床粘接技巧,包括粘接中需要注意的问题,供大家分享交流。方法：选取无托槽隐形矫治器17例,根据临床矫治设计方案共需粘结96个附件。所有操作均为四手操作。结果：所有病例均取得很好的附件外观形态,模板脱位顺利,附件与矫治器贴合。4例附件于矫治过程中脱落,须重新进行粘结。结论：此种附件粘接技巧完全满足临床应用。