How do you determine if a lesion in the renal (UTUC) pelvis is stage Tis, stage one, or stage two?

From the Guidelines

The determination of whether a lesion in the renal pelvis is stage Tis, stage 1, or stage 2 is primarily made through histopathological examination of tissue samples obtained during ureteroscopic biopsy or after nephroureterectomy, with imaging studies like CT urography providing preliminary information. The distinction between stage 1 and stage 2 depends on the depth of tumor invasion, with stage 1 (T1) indicating invasion of the subepithelial connective tissue but not the muscularis propria, and stage 2 (T2) indicating invasion of the muscularis propria 1.

Key Considerations for Staging

• Histopathological examination is the gold standard for determining the stage of upper tract urothelial carcinoma (UTUC) in the renal pelvis.
• Imaging studies, particularly CT urography, can provide valuable preliminary information but are not definitive for staging.
• The depth of tumor invasion is critical for distinguishing between stage 1 and stage 2, with implications for treatment planning.

Role of Imaging in Staging

• CT urography is the preferred imaging modality for the diagnosis and staging of UTUC, offering high sensitivity and specificity for identifying urothelial carcinomas 1.
• MRI and ureteroscopy with visualization can also be used, but CT urography is generally considered the most accurate and comprehensive method.
• Imaging can help identify features suggestive of more advanced disease, such as hydronephrosis or lymph node involvement, but tissue analysis is necessary for definitive staging.

Treatment Implications

• The distinction between stage 1 and stage 2 UTUC is crucial for treatment planning, with more advanced stages potentially requiring more aggressive management, including radical nephroureterectomy with bladder cuff excision 1.
• Kidney-sparing management options, such as endoscopic laser ablation, may be considered for low-risk tumors, while high-risk tumors typically require more definitive surgical intervention.

Recent Guidelines and Recommendations

• Recent guidelines from the European Association of Urology and the American Urology Association emphasize the importance of accurate staging for UTUC, with CT urography playing a central role in the diagnostic process 1.
• The use of adjuvant chemotherapy and immunotherapy in the management of UTUC is an area of ongoing research, with some evidence supporting the benefit of these approaches in certain cases 1.

From the Research

Determining the Stage of a Lesion in the Renal Pelvis

To determine if a lesion in the renal pelvis is stage Tis, stage one, or stage two, several diagnostic methods can be employed. These include:

• Imaging techniques such as computed tomography urography, which remains a gold standard 2
• Urine-based tests, including urinary cytology, although these have been found to be poorly researched or not accurate enough to use solely 2
• Endoscopic methods, such as ureterorenoscopy, which can facilitate proper visualization of the tumor 2
• Biopsy, which can be performed using a basket in papillary lesions and cold-cup biopsy of flat or sessile lesions 2

Staging Accuracy

The accuracy of these methods in determining the stage of a lesion can vary. For example:

• Ureterorenoscopy with biopsy can accurately map upper tract urothelial carcinoma in the majority of patients, but up to 25% of patients will have missed lesions, and nearly 50% of these patients will have a missed carcinoma in situ lesion 3
• A multi-biopsy ureteroscopic approach can provide the tissue diagnosis of urothelial carcinoma in 89% of cases and predict exact histopathological grade in 78%, although it is not accurate as a staging modality 4
• The combination of urinary cytology and biopsy can increase diagnostic sensitivities, particularly for high-grade upper tract urothelial carcinoma 5

Diagnostic Considerations

When determining the stage of a lesion, it is essential to consider the following:

• The location of the lesion, with the most common locations for missed lesions being in the ureter and renal pelvis 3
• The grade of the tumor, with high-grade tumors being more easily detected by urinary cytology and biopsy 5
• The use of new optical and image enhancement techniques, which are being developed to facilitate real-time diagnostics with increased accuracy 6