Xp11.2 translocation renal neoplasm with features of TFE3 rearrangement associated renal cell carcinoma and Xp11 translocation renal mesenchymal tumor with melanocytic differentiation harboring NONO-TFE3 fusion gene

Xp11.2 translocation/TFE3 rearrangement-associated renal cell carcinoma (RCC) and Xp11 translocation renal mesenchymal tumor are distinct tumor entity. To broaden the spectrum of Xp11 neoplasms, we investigated a novel tumor exhibiting morphologies overlapping Xp11.2 translocation/TFE3 rearrangement-associated RCC and the mesenchymal counterpart with melanocytic differentiation by immunohistochemistry, fluorescence in situ hybridization (FISH) and RNA sequencing, as well as literature review. Histologically, the tumor was composed of three different types of tumor cells, including a large proportion of clear cells, small round cells, and a few spindle cells, presenting a relatively clear border in the majority area. The nuclei of all tumor cells showed extensively and strong positive expressions of TFE3. Whereas, the clear cells positively expressed the RCC-related markers including PAX8, RCC marker and CD10, and negatively expressed HMB45; On the contrary, the small round cells and spindle cells positively expressed melanocytic marker HMB45, and negatively expressed PAX8, RCC marker and CD10. The ki67 index was higher in the small round cells and spindle cells than that in the clear cells. FISH revealed the rearrangement of TFE3 gene in all the three types of cells. The NONO-TFE3 fusion gene was detected in all tumor cells by RNA sequencing. This unique Xp11 translocation-associated neoplasm might represent a distinct entity overlapping Xp11 translocation RCC and the mesenchymal counterpart with melanocytic differentiation, broadening the spectrum of Xp11 neoplasms. The patient died of tumor recurrence and lung metastasis after seven months after the surgery suggesting those tumors have an unfavorable prognosis.     

Pseudocapsule of renal cell carcinoma associated with Xp11.2 translocation/TFE3 gene fusion: a clue for tumor enucleation?

Objectives: To evaluate the feasibility and efficacy of tumor enucleation (TE) for patients with small renal cell carcinoma (RCC) associated with Xp11.2 translocation/TFE3 gene fusion (Xp11.2 RCC) by analyzing the pseudocapsule characteristics of Xp11.2 RCCs comparing with that of clear cell renal cell carcinoma (ccRCC). Methods: From June 2007 to February 2014, 22 patients with Xp11.2 RCC who were diagnosed by fluorescence in-situ hybridization polyclonal (FISH) assay and 32 patients with ccRCC treated in our institution were comparatively studied. 12 patients with ccRCC underwent radical nephrectomy (RN) and 20 received TE. Among 22 patients with Xp11.2 RCC, 19 were treated by RN and 3 by TE (1 by radiofrequency ablation assisted TE). Pseudocapsule and other clinicopathological characteristics of the two subtypes of RCC were compared. Survival of patients treated with different surgical methods was evaluated and compared. Results: Pseudocapsule incidence of Xp11.2 RCC (14/22, 63.6%) was lower than that of ccRCC (32/32, 100%, P<0.001). However, pseudocapsule integrity rate of Xp11.2 RCC (10/14, 71.4%) was comparable with that of ccRCC (23/32, 71.9%, P=1.000). The 5-year overall survival of patients with ccRCC treated with RN and TE was 86% and 81%, respectively (P=0.845). Three patients with small Xp11.2 RCC performed well after TE. Conclusions: Over half Xp11.2 RCC had pseudocapsules, whose integrity rate was comparable to that of ccRCC. Treatment effectives of TE and RN were comparable in ccRCC. A preliminary attempt to treat small Xp11.2 RCC with intact pseudocapsule by using TE produced a favorable treatment outcome.     

Fine‐needle aspiration findings of Xp11 translocation renal cell carcinoma metastatic to a hilar lymph node

Xp11 translocation renal cell carcinoma (RCC) is a specific type of renal cell carcinoma recently placed under the “MiT family translocation RCC” at the last 2013 ISUP Vancouver classification of renal neoplasia. This tumor contains variable proportions of clear cells and could easily mimic papillary RCC, clear cell type, and clear cell papillary RCC. Given the small number of published cytologic findings of this tumor, it could easily present as a diagnostic pitfall. We describe a case of a 23‐year‐old man with a history of prior nephrectomy who presented with multiple mediastinal lymphadenopathies on imaging surveillance follow‐up. Fine‐needle aspiration of the lymph node showed tumor cells with voluminous clear to eosinophilic cytoplasm, well‐defined cell borders and hyperchromatic nuclei arranged in papillary architecture. Review of the prior nephrectomy specimen showed papillary cores surrounded by cells with voluminous clear to finely granular eosinophilic cytoplasm and distinct cell borders. Immunohistochemical stains performed on the nephrectomy specimen showed tumor positivity for CD10, E‐cadherin, a‐methylacyl coenzyme A racemase, and TFE3 supporting the diagnosis of Xp11 translocation renal cell carcinoma. Although this tumor was initially described predominantly in children, it could also occur in adults, as seen in this case. Familiarity with the cytologic findings of this tumor, use of immunohistochemical stains, or cytogenetic test to determine the type of gene fusion will be extremely useful in arriving at the correct diagnosis. Diagn. Cytopathol. 2017;45:456–462. © 2017 Wiley Periodicals, Inc.     

青少年肾细胞癌的临床病理及分子遗传学研究

目的 探讨青少年肾细胞癌的临床病理特征、遗传学改变、鉴别诊断及预后.方法 对46例青少年肾细胞癌进行光镜观察及免疫组织化学染色,随访并复习相关文献.对46例肿瘤进行von Hippel-Lindau(VHL)基因区域杂合性缺失(LOH)及VHL基因突变筛查.结果 共诊断19例Xp11.2易位/TFE3基因融合相关性肾癌(Xp11 RCC)、9例透明细胞癌、17例乳头状肾细胞癌(PRCC)和1例不能分类肾细胞癌.19例Xp11 RCC均TFE3阳性,而TFEB阴性.8例肿瘤具有巢状和乳头状结构形态类似t(X;17)ASPL-TFE3型肾癌,6例肿瘤组织学类似t(X;1)PRCC-TFE3型肾癌,4例肿瘤形态像透明细胞癌,1例肿瘤组织学形态文献中未被检索到,表现为细胞核呈毛玻璃样,核仁不明显,可见核沟,肿瘤间质见大量黏液.LOH及VHL突变检测结果显示,仅1例透明细胞癌和1例2型PRCC存在LOH,并且该2型PRCC的VHL基因的一个剪切位点存在胚系突变,553+5 G→C.其余45例均未检测出VHL突变.统计学分析表明TFE3阳性肾细胞癌比TFE3阴性肾细胞癌更倾向于高病理分期(pT3/pT4),并且预后较差(P=0.035).结论 青少年肾细胞癌表现出不同的组织学形态以及分子遗传学背景.其中Xp11 RCC为最常见的肾癌亚型.TFE3阳性肾细胞癌的预后要差于TFE3阴性肾细胞癌.     

Xp11.2易位/TFE3基因融合相关性肾癌的临床病理学特点

目的 探讨Xp11.2易位/TFE3基因融合相关性肾癌的临床病理学特点.方法 对4例Xp11.2易位/TFE3基因融合相关性肾癌进行临床资料分析、组织学观察和免疫组化研究,并复习相关文献.结果 4例患者年龄自6～20岁,均具有腰痛的症状和较高的临床分期.肿瘤最大径2.5～10 cm,切面灰黄间灰红色.组织学上,肿瘤显示乳头状和腺泡状2种生长方式, 间质可见钙化.肿瘤细胞界限清楚,胞质淡红染至透亮,染色质呈泡状,核仁易见.4例肿瘤均弥漫高表达TFE3和CD10,不同程度表达CK、EMA和vimentin.结论 Xp11.2易位/TFE3基因融合相关性肾癌是最近被定义的一种罕见肿瘤,好发于年轻患者,预后较差.其诊断主要依靠特征性的组织病理学改变和免疫标记TFE3阳性.     

Das Translokationskarzinom

The MiT family of translocation-associated renal cell carcinomas comprise approximately 40?% of renal cell carcinomas in young patients but only up to 4?% of renal cell carcinomas in adult patients. The Xp11.2 translocation-associated tumors are the most frequent and were included in the 2004 World Health Organization (WHO) classification. They contain a fusion of the TFE3 gene with ASPSCR1, PRCC, NONO, SPFQ or CLTC resulting in an immunohistochemically detectable nuclear overexpression of TFE3. The Xp11.2 translocation-associated renal cell carcinomas are characterized by ample clear cytoplasm, papillary architecture and abundant psammoma bodies. The TFEB translocation-associated renal cell carcinomas are much rarer and show a biphasic architecture. Fluorescence in situ hybridization permits the detection of a translocation by means of a break apart probe for the TFE3 and TFEB genes and is recommended for the diagnosis of renal cell carcinomas in patients under 30 years of age. The TFE3 and TFEB translocation-associated tumors are classified as MiT family translocation carcinomas in the new WHO classification.The rare renal cell carcinomas harboring an ALK rearrangement with fusion to VCL in young patients with sickle cell trait show a characteristic morphology and are listed in the new WHO classification as a provisional entity.     

Renal cell carcinoma in children and young adults: analysis of clinicopathological, immunohistochemical and molecular characteristics with an emphasis on the spectrum of Xp11.2 translocation-associated and unusual clear cell subtypes

Aims: Recent studies suggest that paediatric renal cell carcinoma (RCC) may represent a distinct group of tumours; however, its biological behaviour and classification remain poorly understood. The aim was to analyse 13 RCCs from patients ≤23 years of age to determine their clinicopathological, immunohistochemical and molecular characteristics. Methods and results: The histological spectrum included: Xp11.2 translocation‐associated (6/13 patients, 46%), clear cell (5/13 patients, 38%), papillary (1/13 patients) and unclassified (1/13 patients) types. The Xp11.2 translocation‐associated RCCs had a wide morphological spectrum, with high nuclear grade cells with abundant cytoplasm ranging from clear to granular and architecture ranging from solid to papillary. These tumours lacked cytokeratin expression and were confirmed by nuclear reactivity for TFE3 protein. Most of these translocation‐associated tumours presented at high stage and had an unfavourable outcome. Three clear cell RCCs had unusual features that have not been previously characterized, including solid and cystic architecture, cells with abundant eosinophilic cytoplasm yet low nuclear grade and focal cytoplasmic inclusions, resembling oncocytoma. Deletion of subtelomeric 3p25 was observed in two of these RCCs. Conclusions: Xp11.2 translocation‐associated RCC represents a predominant and aggressive subtype in the paediatric age group. Increased awareness of this subtype is important due to its heterogeneous morphology.     

Recent classification of renal epithelial tumors

The recent classification of renal tumors is based on genetic evidence as well as on histologic features. Malignant tumor includes clear cell renal carcinoma (RCC), multilocular cystic RCC, papillary RCC, chromophobe RCC, carcinoma of the collecting duct of Bellini, renal carcinoma associated with Xp11.2 translocations/TFE3 gene fusions and mucinous tubular and spindle cell carcinoma. Benign tumor is subdivided into papillary adenoma, renal oncocytoma and metanephric adenoma. Recently, new disease entities such as acquired cystic disease-associated RCC, clear cell papillary RCC and renal carcinoma with t(6;11)(p21:q12) have been discovered. In this article, we briefly review and introduce the clinical, morphological and genetic features of these tumor entities.