To evaluate the clinicopathologic value of morphological growth patterns of small renal cell carcinoma (sRCC) and determine the actual demand for taking a rim of healthy parenchyma to avoid positive SM. Data was collected from 560 sRCC patients who underwent laparoscopic surgeries from May 2010 to October 2017. One hundred forty-nine cases received nephron-sparing surgery (NSS) and others received radical nephrectomy (RN). All specimens were analyzed separately by two uropathologists, and three morphological growth patterns were identified. The presence of pseudocapsule (PC), surgical margins (SM), and other routine variables were recorded. The relationship between growth patterns and included variables was measured by the χ2 test and Fisher’s exact probability test. Survival outcomes were evaluated by Kaplan-Meier method and the log-rank test. The median age of patients was 63.2 years old and the mean tumor diameter was 3.0 cm. Four hundred eighty (85.7%) cases were clear cell RCC and 541 (96.6%) cases were at the pT1a stage. Peritumoral PC was detected in 512 (92.5%) specimens, and the ratio of tumor invasion in PC in infiltration pattern increased obviously than that of the other growth patterns. Similarly, the pT stage was significantly correlated with the infiltration pattern as well. One hundred forty-nine patients underwent NSS and 3 (2.0%) of them showed positive SM after operation. Statistical differences of the 5-year overall survival (OS) and the cancer-specific survival (CSS) existed between different morphological growth patterns, PC status, and pT stages. Morphological growth patterns of sRCC might be used as a potential biomarker to help operate NSS to avoid the risk of positive SM. How to distinguish different morphological growth patterns before operation and the effectiveness of the growth pattern as a novel proposed parameter to direct NSS in sRCC patients deserves further exploration.

中文翻译：

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基于个体肿瘤生长模式的保留肾单位手术安全切缘的组织病理学验证

评估小肾细胞癌 (sRCC) 形态学生长模式的临床病理学价值，并确定采取健康实质边缘以避免阳性 SM 的实际需求。数据来自 2010 年 5 月至 2017 年 10 月接受腹腔镜手术的 560 名 sRCC 患者。 149 例接受了保留肾单位手术 (NSS)，其他接受了根治性肾切除术 (RN)。所有标本均由两名泌尿病理学家分别分析，并确定了三种形态学生长模式。记录假包膜 (PC)、手术切缘 (SM) 和其他常规变量的存在。生长模式和包含变量之间的关系通过 χ2 检验和 Fisher 精确概率检验来衡量。通过 Kaplan-Meier 方法和对数秩检验评估生存结果。患者的中位年龄为 63.2 岁，平均肿瘤直径为 3.0 cm。480 例（85.7%）为透明细胞 RCC，541 例（96.6%）为 pT1a 期。在512个（92.5%）标本中检测到瘤周PC，浸润模式的PC中肿瘤侵袭的比例明显高于其他生长模式。同样，pT 阶段也与浸润模式显着相关。149 名患者接受了 NSS，其中 3 名（2.0%）在手术后显示出阳性 SM。不同形态生长模式、PC 状态和 pT 阶段之间存在 5 年总生存率 (OS) 和癌症特异性生存率 (CSS) 的统计差异。sRCC 的形态生长模式可能被用作潜在的生物标志物，以帮助操作 NSS 以避免阳性 SM 的风险。如何在手术前区分不同的形态生长模式以及生长模式作为指导 sRCC 患者 NSS 的新提议参数的有效性值得进一步探索。