Introduction: Image-guided renal mass biopsy is gaining increased diagnostic acceptance, but there are limited data concerning the safety and diagnostic yield of biopsy for small renal masses (≤4 cm). This study evaluated the safety, diagnostic yield, and management after image-guided percutaneous biopsy for small renal masses. Methods: A retrospective IRB-approved study was conducted on patients who underwent renal mass biopsy for histopathologic diagnosis at a single center from 2015 to 2021. Patients with a prior history of malignancy or a renal mass >4 cm were excluded. Descriptive statistics were used to summarize patient demographics, tumor size, the imaging modality used for biopsy, procedure details, complications, pathological diagnosis, and post-biopsy management. A biopsy was considered successful when the specimen was sufficient for diagnosis without need for a repeat biopsy. Complications were graded according to the SIR classification of adverse events. A chi-squared test (significance level set atp≤ 0.05) was used to compare the success rate of biopsies in different lesion size groups. Results: A total of 167 patients met the inclusion criteria. The median age was 65 years (range: 26–87) and 51% were male. The median renal mass size was 2.6 cm (range: one–four). Ultrasound was solely employed in 60% of procedures, CT in 33%, a combination of US/CT in 6%, and MRI in one case. With on-site cytopathology, the median number of specimens obtained per procedure was four (range: one–nine). The overall complication rate was 5%. Grade A complications were seen in 4% (n= 7), consisting of perinephric hematoma (n= 6) and retroperitoneal hematoma (n= 1). There was one grade B complication (0.5%; pain) and one grade D complication (0.5%; pyelonephritis). There was no patient mortality within 30 days post-biopsy. Biopsy was successful in 88% of cases. A sub-group analysis showed a success rate of 85% in tumors <3 cm and 93% in tumors ≥3 cm (p= 0.01). Pathological diagnoses included renal cell carcinoma (65%), oncocytoma (18%), clear cell papillary renal cell tumors (9%), angiomyolipoma (4%), xanthogranulomatous pyelonephritis (1%), lymphoma (1%), high-grade papillary urothelial carcinoma (1%), and metanephric adenoma (1%), revealing benign diagnosis in 30% of cases. The most common treatment was surgery (40%), followed by percutaneous cryoablation (22%). In total, 37% of patients were managed conservatively, and one patient received chemotherapy. Conclusion: This study demonstrates the safety and diagnostic efficacy of image-guided biopsy of small renal masses. The diagnostic yield was significantly higher for masses 3–4 cm in size compared to those <3 cm. The biopsy results showed a high percentage of benign diagnoses and informed treatment decisions in most patients.
引言：影像引导下肾肿块活检的诊断价值日益获得认可，但针对小肾肿块（≤4厘米）活检的安全性及诊断效能数据仍有限。本研究旨在评估影像引导经皮穿刺活检对小肾肿块的安全性、诊断效能及后续临床管理。 方法：本研究为经机构审查委员会批准的单中心回顾性研究，纳入2015至2021年间为明确组织病理诊断接受肾肿块活检的患者。排除既往恶性肿瘤史或肾肿块直径＞4厘米者。采用描述性统计总结患者人口学特征、肿瘤大小、活检影像引导方式、操作细节、并发症、病理诊断及活检后管理。当获取标本足以明确诊断且无需重复活检时，视为活检成功。并发症分级参照介入放射学会不良事件分类标准。采用卡方检验（显著性水平设定为p≤0.05）比较不同病灶大小分组的活检成功率。 结果：共167例患者符合纳入标准。中位年龄65岁（范围：26-87岁），男性占51%。肾肿块中位直径2.6厘米（范围：1-4厘米）。60%的活检操作单独使用超声引导，33%使用CT引导，6%联合使用超声/CT引导，1例使用MRI引导。在术中细胞病理学评估支持下，单次操作获取标本中位数为4份（范围：1-9份）。总体并发症发生率为5%，其中A级并发症占4%（n=7），包括肾周血肿（n=6）和腹膜后血肿（n=1）；B级并发症1例（0.5%，疼痛）；D级并发症1例（0.5%，肾盂肾炎）。活检后30天内无患者死亡。总体活检成功率为88%。亚组分析显示：直径＜3厘米肿瘤活检成功率为85%，≥3厘米肿瘤为93%（p=0.01）。病理诊断包括：肾细胞癌（65%）、嗜酸细胞瘤（18%）、透明细胞乳头状肾细胞肿瘤（9%）、血管平滑肌脂肪瘤（4%）、黄色肉芽肿性肾盂肾炎（1%）、淋巴瘤（1%）、高级别乳头状尿路上皮癌（1%）及后肾腺瘤（1%），其中良性诊断占比达30%。手术治疗为最主要干预方式（40%），其次为经皮冷冻消融（22%）。总计37%患者采取保守治疗，1例患者接受化疗。 结论：本研究证实影像引导下小肾肿块活检具有良好安全性及诊断效能。直径3-4厘米肿块的诊断成功率显著高于＜3厘米肿块。活检结果显示较高比例的良性诊断，为大多数患者的治疗决策提供了关键依据。
Safety and Diagnostic Efficacy of Image-Guided Biopsy of Small Renal Masses
肿瘤(癌症)患者之家