Abstract：
ALK-rearranged renal cell carcinoma (ALK-RCC) is a very rare novel molecularly defined entity in the recently published fifth edition of the World Health Organization classification of tumours. We describe a case of ALK-RCC in a 76-year-old female. The tumour was composed of discohesive rhabdoid cells and pleomorphic, multinucleated cells (equivalent to ISUP/WHO grade 4). The tumour showed expression with PAX8, Keratin 7 and alpha methylacyl CoA racemase. ALK (D5F3 clone) was strongly and diffusely positive. ALK-FISH showed significant split signals of ALK, confirming the diagnosis. RNA sequencing showed TPM3::ALK rearrangement. Including the current case, there are 14 reported ALK-RCC cases with the same TPM3 fusion partner gene. Review of these published cases highlights their morphological heterogeneity and stresses the importance of running ALK immunohistochemistry on difficult cases to classify renal tumours. This is important while identification of ALK-RCC has clinical significance due to the availability of targeted therapy with ALK inhibitors.
摘要：
ALK重排的肾细胞癌（ALK-RCC）是世界卫生组织最近发布的第五版肿瘤分类中非常罕见的新型分子定义实体。我们描述了一名76岁女性的ALK-RCC病例。肿瘤是由盘形性横纹肌样细胞和多形性，多核细胞（相当于ISUP/WHO4级）。肿瘤显示PAX8，角蛋白7和α甲基酰基辅酶A消旋酶的表达。ALK（D5F3克隆）强烈且呈弥漫性阳性。ALK-FISH显示显著的ALK分裂信号,确认诊断。RNA测序显示TPM3::ALK重排。包括目前的情况,有14例报道具有相同TPM3融合伴侣基因的ALK-RCC病例。对这些已发表病例的回顾强调了它们的形态异质性，并强调了对困难病例进行ALK免疫组织化学以对肾脏肿瘤进行分类的重要性。这一点很重要，而ALK-RCC的鉴定由于ALK抑制剂靶向治疗的可用性而具有临床意义。
