Renal tumors in solid organ recipients: clinical and pathologic features

Area of Science:

• Urology
• Nephrology
• Oncology

Background:

• Solid organ recipients face a significantly increased risk of developing renal cell carcinoma (RCC) compared to the general population.
• Limited data exists on the specific characteristics of RCC in this vulnerable patient group.

Purpose of the Study:

• To characterize renal tumors in solid organ recipients.
• To compare these tumor features with those found in the general population.

Main Methods:

• Retrospective study of patients undergoing surgery for localized renal masses (2000-2008).
• Comparison of demographic, clinical, radiographic, and pathologic data between organ recipients and non-recipients.
• Subanalysis comparing kidney transplant recipients with other solid organ transplant recipients.

Main Results:

• Organ recipients (19/950) were younger, had lower BMI, and were often asymptomatic.
• RCC in recipients showed higher malignancy rates (88.2% vs. 78.7%), smaller size, lower stage/grade, and increased papillary histology (35.3% vs. 19.8%).
• Kidney recipients had nearly 50% papillary RCC, versus 20% in other organ recipients; excellent oncologic outcomes observed with no metastases or RCC deaths.

Conclusions:

• Renal masses in organ recipients are typically incidental, smaller, and more often malignant than in the general population.
• Despite higher malignancy rates, RCC in transplant recipients present at lower stages and grades.
• Surgical management of RCC in organ recipients appears to yield excellent oncologic outcomes.