From the Guidelines
The presence of a soft tissue mass and a 3 mm nodule on surveillance scans after partial nephrectomy for chromophobe RCC does not necessitate immediate intervention, and continued routine surveillance is recommended. Given the patient's history of successful partial nephrectomy for a small chromophobe renal cell carcinoma, the recent scan findings of a biopsied soft tissue mass confirmed as benign fat necrosis with inflammation and fibrosis, and a small 3 mm nodule in the fat anterior to the psoas muscle, are likely representative of post-surgical changes rather than recurrent disease 1. The nodule's appearance shortly after surgery and gradual maturation over three years without significant growth suggests a benign etiology, such as scarring or inflammatory change. For chromophobe RCC with initial T1a staging and no adverse features, standard surveillance should continue with periodic imaging, typically annual or biannual abdominal imaging, for at least 5 years post-surgery 1. Key factors influencing the decision for continued surveillance include:
- The favorable histology of chromophobe RCC without sarcomatoid features or necrosis
- The small initial tumor size
- Clean surveillance scans indicating no evidence of recurrence or metastatic disease
- The low recurrence risk associated with T1a tumors As recommended by the European Association of Urology guidelines and the ACR Appropriateness Criteria, routine follow-up is essential for detecting potential recurrences or metastases, with a focus on asymptomatic solitary or oligometastatic disease that may benefit from early salvage treatment 1. Therefore, no specific medications or treatments are needed at this time, and the patient should continue with standard surveillance protocols.
From the Research
Clinical Significance of Soft Tissue Mass and 3 mm Nodule
- The clinical significance of a soft tissue mass and a 3 mm nodule found on surveillance scans after partial nephrectomy for chromophobe RCC can be evaluated using imaging modalities such as MRI and ultrasound 2, 3, 4.
- The majority of soft tissue masses encountered on routine imaging are incidental and benign, but some may require contrast administration, evaluation with other imaging modalities, follow-up imaging, or biopsy for diagnosis 2, 5.
- MRI is the most important and sensitive imaging modality in the differentiation of unclear soft tissue tumors, and a systematic approach can help narrow down the large number of possible differential diagnoses 3, 6.
- A scoring system based on parameters such as margin, maximum diameter, and vascular density can be used to distinguish between malignant and benign masses, with a combination of ultrasound and MRI achieving high sensitivity, specificity, and accuracy 4.
- In cases where the nature of the soft tissue mass is uncertain, a biopsy may be necessary to rule out malignancy 5, 3.