American Board of Internal Medicine (ABIM) Certification Practice Exam

What is the diagnostic imaging workup protocol for small renal cell carcinoma lesions?

1. Immediate nephrectomy

2. Biopsy if possible

3. No imaging is needed

4. Observation only

The correct answer is: Biopsy if possible

For small renal cell carcinoma (RCC) lesions, the recommended approach often includes a biopsy when feasible. This is critical for confirming the diagnosis, particularly given the challenges in differentiating RCC from other renal masses based on imaging alone. Although imaging techniques such as ultrasound, CT scans, or MRI are effective for identifying renal masses, they do not yield definitive histological diagnosis. Biopsy allows for the evaluation of the tumor's cellular characteristics, helping guide treatment decisions and assess tumor aggressiveness. In contrast, immediate nephrectomy may be considered for larger or symptomatic tumors but is not routine for small lesions without histological confirmation of malignancy. Simply observing small renal lesions is also not appropriate without a clearer understanding of their nature, as some may behave aggressively. Lastly, suggesting that no imaging is needed does not align with the typical diagnostic protocols for suspected cancers, which generally incorporate imaging to assess the characteristics and impact of the tumor. Therefore, performing a biopsy when possible is essential in the management of small renal cell carcinoma to establish a definitive diagnosis.