肾内血管内大B细胞淋巴瘤（IVLBCL）是一种罕见、侵袭性的B细胞淋巴瘤，恶性细胞占据血管腔内，目前只有53例患者报道。我们在这里展示了最大的病例系列，以表征这种罕见疾病。我们对肾活检和尸检结果进行了多机构的回顾性复查，并报告了我们的发现。我们确定了20名平均年龄为65.7±7.8岁（55%为男性）的IVLBCL肾生物检的患者。最常见的临床表现是发热和贫血。70%至90%的人群中都发现急性肾损伤（AKI），70%至84.1%的人群中发现蛋白尿，45%的人群中发现血尿，10%至26.1%的患者发生肾病综合征。血清肌酐的中位数（四分位数范围）为1.75（1.14，3.3）mg/dl。恶性淋巴细胞存在于肾小球、肾小管周围毛细血管以及动脉或静脉中。44.3%的患者显示出肾外浸润至骨髓、肝脏、脾脏、中枢神经系统、肺和皮肤。肿瘤细胞表达CD20、CD79a、PAX-5和MUM1+，并且为CD10阴性。可获得的随访数据显示，诊断后中位生存期为21个月。肾外浸润是一个重要的、独立的死亡率预测因素，经年龄和性别控制后，风险比为4.975（95%置信区间：1.38、17.88）。血清肌酐、年龄、性别和肾内动脉或静脉的浸润对生存率没有影响。肾IVLBCL是一种罕见疾病，通常在肾生物检中意外发现，表现为发热、贫血、轻度AKI和蛋白尿。中位生存期为21个月，肾外浸润与恶化的预后相关联。© 2022由国际肾脏学会代表Elsevier Inc.发布。

Renal intravascular large B-cell lymphoma (IVLBCL) is a rare, aggressive B-cell lymphoma with neoplastic cells occupying the vascular lumina with only 53 patients reported to date. Here, we present the largest case series to characterize this rare disease.We performed a multi-institutional, retrospective review of kidney biopsies and autopsies with a diagnosis of kidney IVLBCL and report our findings.We identified 20 patients with an average age of 65.7 ± 7.8 years (55% males) with IVLBCL on kidney biopsy. The most common clinical presentation was fever and anemia. Acute kidney injury (AKI) was noted in 70% to 90%, proteinuria in 70% to 84.1%, hematuria in 45%, and nephrotic-range proteinuria in 10% to 26.1% of cases. The median (interquartile range) of serum creatinine was 1.75 (1.14, 3.3) mg/dl. Neoplastic lymphoid cells were present in glomeruli, peritubular capillaries, and arteries or veins. Of the patients, 44.3% showed extrarenal infiltration into bone marrow, liver, spleen, central vervous system, lung and skin. Neoplastic cells express CD20, CD79a, PAX-5, and MUM1+, and were CD10-negative. Available follow-up data showed a median survival of 21 months after diagnosis. Extrarenal involvement is a significant and independent predictor of mortality with a hazard ratio of 4.975 (95% confidence interval:1.38, 17.88) after controlling for age and gender. Serum creatinine, age, sex, and infiltration of intrarenal arteries or veins did not affect survival.Kidney IVLBCL is a rare disease that is unexpectedly diagnosed by kidney biopsy, presenting with fever, anemia, mild AKI, and proteinuria. Median survival is 21 months and extrarenal involvement is associated with worse outcome.© 2022 Published by Elsevier Inc. on behalf of the International Society of Nephrology.