From the Guidelines
The CT scan showing no evidence of urothelial carcinoma is a reassuring finding, but it does not completely rule out the presence of small or early-stage lesions, and additional testing such as cystoscopy may still be necessary, especially if symptoms persist 1. The CT scan is a valuable diagnostic tool, but it has limitations in detecting small or flat lesions that may be more easily detected by cystoscopy, with a diagnostic accuracy of 91% in detecting urothelial carcinomas 1. If cystoscopy is performed first, CTU is used to detect isolated or concurrent upper tract lesions, because approximately 2% to 4% of patients with bladder cancer may have concurrent UTUC 1. Some of the limitations of CTU include technical factors such as large postvoid residual with suboptimal opacification of the bladder, and artifacts obscuring the bladder, which can lead to false-negatives 1. Given these limitations, it is essential to interpret the CT scan results in the context of the complete clinical picture, including symptoms, risk factors, and other test results, and to consider additional testing if clinical suspicions persist 1. Key points to consider include:
- The CT scan has a high diagnostic accuracy, but it is not perfect and may miss small or flat lesions 1
- Additional testing such as cystoscopy may be necessary to rule out urothelial carcinoma, especially if symptoms persist 1
- The absence of findings on CT provides reassurance, but it should be interpreted in the context of the complete clinical picture 1
- Regular follow-up is recommended if there were clinical suspicions that prompted the CT scan initially, as some cancers may develop or become visible on imaging over time 1.
From the Research
Urothelial Carcinoma Diagnosis
- The absence of evidence of urothelial carcinoma on CT scans does not necessarily rule out the presence of the disease, as it may be present in other parts of the urinary tract or at an early stage that is not detectable by CT scans 2, 3.
- Urine cytology is a crucial diagnostic tool for detecting urothelial carcinoma, but it may not always be accurate, especially in cases where the disease is present in the lower gynecologic tract or rectum 4.
- Other diagnostic techniques, such as methylation-specific polymerase chain reaction and urine biomarker-based ancillary techniques, have shown promise in detecting urothelial carcinoma, especially in patients with gross hematuria 5, 6.
Diagnostic Challenges
- Urothelial carcinoma can be challenging to diagnose, especially in its early stages, due to the lack of specific symptoms and the limitations of current diagnostic techniques 2, 3.
- The presence of a positive urine cytology result does not always indicate the presence of urothelial carcinoma, and further evaluation is often necessary to confirm the diagnosis 4, 6.
- The use of complementary diagnostic techniques, such as cystoscopy and biopsy, is often necessary to confirm the presence of urothelial carcinoma and to determine the extent of the disease 3, 6.
Diagnostic Techniques
- Cystoscopy is a commonly used diagnostic technique for detecting urothelial carcinoma, but it can be invasive and may not always detect the disease, especially in its early stages 3, 6.
- Urine biomarker-based ancillary techniques, such as the UroVysion fluorescence in situ hybridization (FISH) assay and the 8-gene expression classifier (GEC), have shown promise in detecting urothelial carcinoma, especially in patients with suspicious urine cytology results 6.
- Methylation-specific polymerase chain reaction is a non-invasive diagnostic technique that has shown promise in detecting urothelial carcinoma, especially in patients with gross hematuria 5.