From the Guidelines
I strongly recommend continued surveillance with regular CT imaging for this 3mm nodule that appeared three years after partial nephrectomy for stage 1 chromophobe renal cell carcinoma (RCC), as the risk of malignancy is low and the nodule has remained stable. The patient's history of stage 1 chromophobe RCC, a subtype with a favorable prognosis, and the stability of the nodule over three years, suggests that immediate intervention is not necessary. Follow-up should include contrast-enhanced CT scans every 6-12 months for at least 5 years post-surgery, with comprehensive evaluation of both the surgical site and potential metastatic locations, as recommended by the ACR Appropriateness Criteria 1. If the nodule remains stable, the interval between scans can gradually increase after 5 years. Should the nodule grow significantly (>5mm increase) or if new nodules appear, further evaluation with possible biopsy or PET-CT would be warranted, as suggested by the guidelines for post-treatment follow-up and active surveillance of clinically localized renal cell carcinoma 1. The stability over three years is reassuring, as chromophobe RCC typically has a lower metastatic potential than other RCC subtypes, with recurrence rates of only 5-10% for stage 1 disease. It is essential to weigh the risks and benefits of continued surveillance versus intervention, considering the patient's individual risk factors and the potential consequences of overtreatment or undertreatment, as emphasized in the AUA guideline for follow-up for clinically localized renal neoplasms 1. Regular follow-up with CT imaging will enable early detection of any changes in the nodule or the development of new lesions, allowing for timely intervention if necessary. Ultimately, the goal of surveillance is to balance the risk of recurrence with the risks associated with repeated imaging and potential interventions, prioritizing the patient's quality of life and minimizing morbidity and mortality.
From the Research
Significance of a Persistent 3mm Nodule
- A persistent 3mm nodule in the fat anterior to the psoas muscle, below the lower pole of the left kidney, 3 years after partial nephrectomy for stage 1 Chromophobe Renal Cell Carcinoma (RCC) may be a cause for concern due to the potential for recurrence of RCC 2.
- Chromophobe RCC is a rare subtype of RCC, accounting for 5% of cases, and is known for its favorable clinical course and better prognosis compared to clear cell RCC 3, 4.
- However, RCC is known for its potential recurrence, sometimes several years after initial management, and can metastasize to various sites, including the liver, kidney, or bone 2.
- The presence of a nodule in the fat anterior to the psoas muscle may be indicative of a metastatic lesion, although the small size of the nodule (3mm) may make it difficult to determine its significance without further evaluation 5.
- Studies have implicated a prognostic role of lymph node involvement at the time of initial diagnosis to predict future recurrence, highlighting the importance of thorough evaluation and follow-up 2.
Potential Implications
- The nodule may be a sign of recurrent RCC, which would require further evaluation and potentially additional treatment 2, 3.
- Alternatively, the nodule may be a benign lesion, such as a cyst or a fibrotic scar, which would not require further intervention 4.
- Further imaging studies, such as CT or MRI, may be necessary to characterize the nodule and determine its significance 4.
- In patients with a history of RCC, it is essential to consider the possibility of intratumoral metastasis to the renal tumor, especially in cases with multiple cancers and an increase in renal tumor size 5.