From the Guidelines
The diagnostic workup for renal cell carcinoma (RCC) should begin with imaging studies, including contrast-enhanced computed tomography (CT) of the chest, abdomen, and pelvis, as it is the most accurate method for detecting and staging RCC 1. The initial evaluation of RCC typically involves imaging studies, such as ultrasound, CT scan with contrast, and MRI.
- CT scans are particularly valuable as they can detect small tumors and provide information about tumor extension and metastasis.
- Urinalysis may show hematuria in some cases, though this finding is not specific to RCC.
- Blood tests, including complete blood count, comprehensive metabolic panel, and markers like erythrocyte sedimentation rate, may reveal anemia, elevated liver enzymes, or hypercalcemia in advanced disease. The definitive diagnosis requires tissue sampling, usually through CT-guided percutaneous biopsy or during surgical removal of the tumor.
- In cases where metastatic disease is suspected, additional imaging such as chest CT, bone scan, or brain MRI may be necessary.
- PET scans are sometimes used but are not standard for initial diagnosis, as stated in the ESMO clinical practice guideline for diagnosis, treatment, and follow-up of RCC 1. Early detection is crucial as RCC is often asymptomatic until advanced stages, with the classic triad of flank pain, hematuria, and palpable abdominal mass occurring in only about 10% of patients.
- Genetic testing may be recommended for patients with family history or early-onset disease to identify hereditary syndromes associated with RCC. It is essential to note that the European Association of Urology guidelines on RCC also recommend the use of CT, ultrasound, and MRI for detecting and characterizing renal masses, and that PET scans are not a standard investigation in the diagnosis and staging of clear-cell RCC 1.
- The AUA guideline for renal mass and localized renal cancer also suggests that patients with findings suggestive of metastatic renal malignancy should be evaluated to define the extent of disease and referred to medical oncology 1.
- Histopathological confirmation of RCC is mandatory for all patients before starting systemic treatment, and core biopsy of the renal tumor or metastatic site provides histopathological confirmation with high sensitivity and specificity, and negligible risk of tumor seeding 1.
From the Research
Diagnostics Tests for Renal Cell Carcinoma
- The most common diagnostics tests for renal cell carcinoma include:
- Computed Tomography (CT) scan: considered the first choice for imaging of renal masses and has been the mainstay for several decades 2, 3, 4, 5
- Magnetic Resonance Imaging (MRI): considered an important alternative in patients requiring further imaging or in cases of allergies, pregnancy, or surveillance 2, 6, 5
- Ultrasound: commonly used for renal imaging, but has limited sensitivity and specificity compared to CT and MRI 2, 3, 5
- Positron Emission Tomography-CT: has good diagnostic accuracy, but limited data is available 5
- The choice of diagnostics test depends on various factors, including patient characteristics, tumor stage, and availability of imaging modalities
- Contrast-enhanced CT and MRI are considered the diagnostic mainstay for renal-cell carcinoma, with almost equally high diagnostic and staging accuracy 5
Imaging Modalities
- CT scan:
- MRI:
- Ultrasound:
Diagnostic Performance
- CT scan: median sensitivity and specificity of 88% and 75%, respectively 5
- MRI: median sensitivity and specificity of 87.5% and 89%, respectively 5
- Ultrasound: varied results depending on the technique, but generally poor diagnostic performance 5
- Positron Emission Tomography-CT: good diagnostic accuracy, but limited data is available 5