Clinicopathological features of non-conventional renal cell carcinoma histological subtypes: Learning points from a large contemporary series spanning over three decades

Outcomes of Localized Renal Cell Carcinoma Across Different Races

Introduction: Epidemiological outcomes of renal cell carcinoma (RCC) remain sparse. This study aims to compare preoperative characteristics, surgical outcomes, and oncological outcomes of RCC patients at a urology unit in Singapore.Methods: A retrospective cohort analysis of 137 RCC patients in the National University Hospital of Singapore who had undergone partial nephrectomy between 2009 and 2020 was conducted. χ2 tests (Chi-Square Test, Fisher's Exact Test) and one-way analysis of variance (ANOVA) were used for comparing categorical and continuous variables respectively. Kaplan-Meier estimates were used for survival analysis.Results: In total, 137 patients were identified (Chinese [n=82], Malay [n=19], Indian [n=15], Others [n=21]). Indian patients were diagnosed at an earlier age (52.13±10.52 years, P=0.018). A larger percentage of Malay patients (78.9%, P<0.001) were operated on before 2016, prior to the center's adoption of the robotic surgical technique. More Malay and Indian patients underwent laparoscopic surgery (36.8% and 46.7%, P=0.008), experiencing higher rates of intra-operative conversions compared to the Chinese and other ethnicities (5.3% and 13.3% vs. 0%, P=0.011). They also had longer post-operative stays compared to Chinese (7.42±6.46 days; 7.40±7.69 days vs. 4.88±2.87 days, P=0.036). Malays were much less likely to undergo robotic partial nephrectomy compared to Chinese patients (OR=0.295, 95% CI=0.102-0.856) and had the highest rate of metastatic recurrence (10.5%, P=0.023).

Contrast-enhanced ultrasound (CEUS) of benign and malignant renal tumors: Distinguishing CEUS features differ with tumor size

BACKGROUND

Contrast-enhanced ultrasound (CEUS) is now a guideline-recommended strategy for diagnosing renal lesions. Tumor size is related to the risk of the treatment and prognosis in renal tumors. Thus, we aim to analyze the CEUS features of solid renal tumors in relation to tumor size.

METHODS

The CEUS appearance of 156 pathologically diagnosed solid renal tumors were retrospectively analyzed. Three groups were stratified according to the tumor size (≤2 cm [group I], 2.1-4 cm [group II] and 4.1-7 cm [group III]). For each group, the features of wash-in type, enhancement degree, enhancement homogeneity, and the presence of a pseudocapsule sign were compared between benign and malignant tumors.

RESULTS

All 156 included lesions were detected by CEUS. The proportion of benign tumors in three size groups was 37.1%, 19.4%, and 20.4%, respectively. The proportion of malignant tumors was highest (80.6%) in group II, followed by group III (79.6%) and group I (62.9%). In group I, malignant and benign tumors differed significantly in the presence of a pseudocapsule sign (p = 0.015) and homogeneity (p = 0.007). In group II, the degree of enhancement differed (p = 0.02) between tumor types. In group III, the two tumor types differed in both the wash-in pattern (p = 0.015) and enhancement degree (p = 0.024). The weighted and Cohen's kappa values for the concordance between inter-observer agreement ranged from 0.31 (95% CI: 0.36-0.57) to 0.90 (95% CI: 0.77-1.00).

CONCLUSIONS

CEUS features of malignant and benign renal tumors change along with the tumor size. The use of CEUS features in the diagnosis of benign and malignant tumors requires consideration of tumor size.