From the Guidelines
The management of Tubulocystic Renal Cell Carcinoma (RCC) primarily involves surgical resection as the first-line treatment, with partial nephrectomy preferred when technically feasible to preserve renal function, as recommended by the European Association of Urology guidelines updated in 2022 1. For localized disease, partial nephrectomy is the preferred approach when possible, to maintain renal function and minimize the risk of metabolic or cardiovascular disorders, as supported by multiple retrospective series and one RCT including patients with organ-confined RCC 1. Active surveillance can be considered for small, incidentally discovered tumors in elderly patients or those with significant comorbidities. Following surgery, regular follow-up with imaging (CT or MRI) every 6-12 months for the first few years, then annually thereafter, is recommended to monitor for recurrence, as outlined in guidelines for post-treatment follow-up and active surveillance of clinically localized renal cell carcinoma 1. Unlike clear cell RCC, tubulocystic RCC generally has a favorable prognosis with low metastatic potential. For the rare cases of metastatic disease, targeted therapies used for other RCC subtypes may be considered, though specific efficacy data for tubulocystic RCC is limited due to its rarity, and management should be guided by principles outlined for metastatic clear cell renal cell carcinoma, including the use of immune checkpoint inhibitors and vascular endothelial growth factor receptor tyrosine kinase inhibitors 1. Multidisciplinary tumor board discussion is valuable for complex cases, ensuring that the management approach is tailored to the individual patient's needs and the typically indolent behavior of tubulocystic RCC. Key considerations in the management of tubulocystic RCC include:
- Surgical approach: Partial nephrectomy vs. radical nephrectomy based on tumor size, location, and patient factors.
- Active surveillance for small, incidentally discovered tumors in selected patients.
- Regular follow-up imaging to monitor for recurrence.
- Consideration of targeted therapies for metastatic disease, although data specific to tubulocystic RCC is limited.
- Multidisciplinary discussion for complex cases to ensure optimal management.
From the Research
Management Approach for Tubulocystic Renal Cell Carcinoma (RCC)
The management approach for Tubulocystic Renal Cell Carcinoma (RCC) is based on several factors, including the tumor's size, location, and aggressiveness.
- Surgical treatment, such as radical nephrectomy or partial nephrectomy, is often considered for patients with localized disease 2.
- Targeted agents and radiofrequency ablation may be used to treat recurrent or metastatic disease, as seen in a case report of a patient with recurrent tubulocystic RCC in the retroperitoneum and contralateral kidney 3.
- The Bosniak classification system may be used to categorize multilocular cystic lesions and guide patient management, although differentiation from other cystic tumors can be challenging 4.
Clinicopathologic Characteristics
Tubulocystic RCC has distinct clinicopathologic characteristics, including:
- Exclusive tubulocystic growth 5
- Male predominance 5
- Tumor size ranging from 0.1 cm to 3.5 cm 5
- Multifocality and peripheral location are common 5
- Association with papillary adenoma(s) and other low-grade/indolent renal cell carcinomas 5
- Background kidney often displays end-stage kidney disease 5
Pathologic Classification
The pathologic classification of tubulocystic RCC is still evolving, with some studies suggesting it may be closely related to papillary renal cell carcinoma (PRCC) 6.
- Cytogenetic analysis has shown similarities between tubulocystic RCC and PRCC, including gains of chromosomes 7 and 17 and loss of Y chromosome 6.
- Some studies propose reclassifying tubulocystic RCC as a tubulocystic renal cell tumor due to its frequent association with end-stage kidney disease and indolent clinical course 5.