[Clinicopathologic features of primary renal neuroendocrine carcinoma].

Objective: To investigate the clinicopathologic characteristics, diagnostic features and prognosis of primary renal neuroendocrine carcinoma (NEC). Methods: The clinicopathologic data of eight cases of renal NEC was collected from January 2008 to December 2017 from Affiliated Hospital of Qingdao University. Immunohistochemical staining was performed, and follow-up information was analyzed, and the relevant literature reviewed. Results: The patients' mean age at diagnosis was 45 years (range, 27-66 years); five were women, and three were men. The tumors located on the left side in five patients, and on the right side in three. Five cases were detected incidentally, and three patients presented with loin pain. Microscopically, these cases included five well-differentiated NECs (three carcinoids, two atypical carcinoids), two small cell NECs, and one large cell NEC according to the World Health Organization classification of 2016. The tumors infiltrated the renal capsule in six cases. Necrosis was found in five cases. Vascular invasion with tumor emboli was seen in three cases. Lymph node metastasis was identified in one case. Immunohistochemically, the expression rates of neuroendocrine markers CD56, chromogranin A (CgA) and synaptophysin (Syn) were 6/8, 4/8, and 8/8 respectively. Some of the NECs were positive for epithelial markers CKpan (6/8, with three cases showing focal positivity) and CAM5.2 (4/8) of variable degrees. The Ki-67 proliferation index was≤3% in the carcinoids; ≥50% in the small cell carcinoma and large cell carcinoma; and 5% and 8% for the two cases of atypical carcinoid, respectively. All cases were negative for EMA, CK7, CA9, CD10, CD117, PAX2, PAX8, WT1, p63, S-100 and TTF1. Three patients (two with small cell carcinoma and one with large cell carcinoma) died of extensive metastases at 3 months, 4 months and 9 months after operation, while five patients were well, without recurrence or distant metastasis for follow-up period of one to nine years. Conclusions: Primary renal NEC is rare. Carcinoid is the most common histological type. The pathomorphological features and neuroendocrine markers (CD56, CgA, Syn), epithelial markers (CKpan, CAM5.2) and nephrogenic markers (PAX2, PAX8) are important for the diagnosis. Renal carcinoid tumors are indolent and prone to early metastasis, but are associated with prolonged survival. The small cell renal cell carcinoma and large cell carcinoma are highly malignant renal tumors with poor prognosis and short survival.目的： 探讨肾脏原发性神经内分泌癌(NEC)的临床病理特征、诊断和预后。 方法： 收集2008年1月至2017年12月青岛大学附属医院和解放军第四〇一医院确诊的肾脏原发性NEC 8例，按照WHO(2016)泌尿系统与男性生殖器官肾肿瘤分类，采用HE及免疫组织化学进行观察，结合文献分析其临床病理学特点。 结果： 患者男3例，女5例，年龄27～66岁，平均年龄45岁。左肾5例，右肾3例。5例因体检发现，3例因腰痛就诊。组织学上，8例NEC包括：高分化神经内分泌肿瘤5例(类癌3例，不典型类癌2例)、小细胞NEC 2例，大细胞NEC 1例。8例中6例侵犯肾被膜，5例伴有坏死，3例间质脉管内查见癌栓，1例出现腔静脉淋巴结转移。免疫组织化学染色：神经内分泌标志物CD56、嗜铬粒素A(CgA)、突触素的阳性表达比例分别为6/8、4/8和8/8，其中8例NEC同时不同程度表达上皮性标志物广谱细胞角蛋白(CKpan，6/8；3例灶状)、CAM5.2(4/8)。Ki-67阳性指数在类癌中≤3%，2例不典型类癌分别为5%和8%，而小细胞癌和大细胞癌均≥50%。所有病例对上皮细胞膜抗原(EMA)、细胞角蛋白(CK)7、碳酸酐酶Ⅸ(CA9)、CD10、CD117、PAX2、PAX8、WT1、p63、S-100蛋白和甲状腺转录因子(TTF)1均不表达。8例NEC患者除3例(2例小细胞癌、1例大细胞癌)分别于术后3、4和9个月因广泛转移死亡外，余5例随访1～9年均健在，未见复发、远处转移。 结论： 肾脏原发性NEC为罕见的肾肿瘤，组织学类型以类癌最多见。依靠病理形态学特点并联合应用神经内分泌标志物(CD56、CgA、突触素)、上皮性标志物(CKpan、CAM5.2)以及肾源性标志物(PAX2、PAX8)对该类肿瘤的诊断及鉴别诊断具有重要意义。肾脏类癌属于低度侵袭性肿瘤，容易出现早期转移，但总体预后良好。小细胞癌和大细胞癌为高度恶性的肾肿瘤，预后极差，生存期很短。.