In our recent study, we examined eight patients presenting with UTUC with VTT who underwent radical nephroureterectomy at our institution. Despite the small cohort, the phenotype that emerged was remarkably consistent.
All tumors presented with locally advanced stage, with the majority demonstrating pT4 disease (75%), and lymph node metastases were common (62.5%). During follow-up, most patients (71%) developed metastatic progression with a short median time-to-progression of 2.4 months. These findings highlight that UTUC with VTT represents a clinically aggressive biological subtype rather than simply an anatomic variant.
One of the most notable observations in our cohort was the high prevalence of sarcomatoid differentiation. Almost 90% of tumors demonstrated sarcomatoid features, and these elements were disproportionately enriched within the VTT component itself. Interestingly, nodal metastases in the corresponding patients retained conventional urothelial carcinoma histology without sarcomatoid differentiation. This spatial separation may reflect distinct drivers between vascular invasion and lymph node metastases.
Several consistent imaging features may help clinicians distinguish UTUC with VTT from renal cell carcinoma preoperatively. Involvement of the collecting system, manifesting as irregular mural thickening and intraluminal filling defects, as well as the infiltrative nature of the primary tumor, were notable in all cases.
These distinctions are clinically important because management pathways differ substantially. While RCC with VTT is typically treated with radical nephrectomy, UTUC requires radical nephroureterectomy with bladder cuff excision and lymphadenectomy. Another important preoperative consideration is the potential role of neoadjuvant systemic therapy, particularly given the short-time-to progression observed in our cohort.
Although limited by the small sample size, our study provides meaningful insights into the distinct biological and clinical features of UTUC with VTT. The findings suggest that this entity represents a particularly aggressive phenotype with a strong association with sarcomatoid differentiation. Clinicians should therefore consider UTUC in the differential diagnosis of renal masses with venous tumor thrombus, particularly when imaging demonstrates involvement of the collecting system and infiltrative growth pattern. Greater awareness of this presentation may help avoid diagnostic misclassification, guide surgical planning, and stimulate further investigation into this rare phenomenon.
Written by:
- Philipp Korn, Department of Urology and Oncology, The Brady Urological Institute, The Johns Hopkins University School of Medicine, Baltimore, MD; Department of Urology, Rechts der Isar Medical Center, School of Medicine and Health, Technical University of Munich, Munich, Germany
- Nirmish Singla, Department of Urology and Oncology, The Brady Urological Institute, The Johns Hopkins University School of Medicine, Baltimore, MD; Department of Urology, Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria.
Read the Abstract