Issues and challenges in small renal masses

15 November 2014

The various approaches in managing small renal masses ranging from the role of imaging, renal biopsy, active surveillance to focal treatments and radiotherapy were closely examined and discussed in the second day plenary session of the 6th European Multidisciplinary Meeting on Urological Cancers (EMUC) in Lisbon, Portugal.
To illustrate the challenges in diagnosing and treating small renal masses, Jochen Walz (FR) presented, for audience voting, a case of a 74-year-old woman with a diagnosis in 2009 of a marginal zone lymphoma , indolent and slow-growing NHL B-cell lymphoma. Her co-morbidities included thyroid node (benign), breast cancer surgery and EBRT in 2004, arrthymia, moderate renal failure and WHO-PFS: 1. The question ‘What other imaging study would you do?’ posed to the audience for voting yielded the following responses:

MRI- 27.9% votes
Contrast enhanced MRI- 34.3%
Contrast enhanced CT- 25%
Ultrasound- 6.4%
PET/CT- 6.4%
The imaging tests showed a hilar lesion, 2 arteries involvement, tumour in close proximity to both arteries, tumor in close proximity to main vein and tumour in close proximity to collecting system. Again the audience was asked to vote regarding their second follow-up diagnostic approach. To the question “What to do now?” the audience voted in the following manner, with majority opting for biopsy:

Curative treatment-  24.3%
TKI treatment- 2.1%
Biopsy- 33.3%
Postpone and re-evaluate in 6 months- 22.8%
Active surveillance- 17.5%
Following the audience voting, speakers Harriet Theony (CH), A. Volpe (IT), Michael Jewett (CA) Maria Pilar Laguna (NL), and Geert De Meerleer (BE) lectured on the various issues that involved imaging, biopsy, surveillance, ablative treatment and radiotherapy.

“The challenge to us is how to characterize the detected mass and identify whether its benign or malignant,” said Theony as she mentioned the available imaging modalities such as MRI, diffusion weighted MRI (DWI) and CT.

“CT and MRI are helpful in predicting the histology of small renal masses based on morphology such as shape, size, location, density and signal intensity,” said Theony adding that patient management also depends on age and co-morbidities. She also emphasized that multi-disciplinary discussions are necessary for an optimal patient management.

Regarding percutaneous renal biopsy, Volpe said it is a safe procedure and adequate cores have good diagnostic yield and accuracy for the diagnosis of malignancy. He noted: “Abdominal imaging does not have optimal accuracy and provides little information for selection of non-surgical management.”

“Percutaneous biopsy is useful for decision-making in several clinical settings,” added Volpe, whilst stressing that renal tumour biopsy is not recommend for cystic lesions Bosniak (less than 3) and has lower diagnostic yield for smaller (

Jewett, meanwhile, explored the issue of active surveillance (AS) and said this approach is often applicable in small renal masses (SRMs).  He, however, highlighted the need for SRMS to be characterized, adding that SRMs can also be sub-typed and can also metastasize. AS can also be offered to older patients and those with frail health.

Laguna described and gave an overview of ablative treatment and said that observational, population-based studies show an increasing use of abalation therapy of SRMS during the last 10 years.

“Ablation procedures preserve renal function and entail a lower risk of complications than minimally invasive partial nephrectomy (MIPN),” she said. “Ablation also exhibits a higher risk of progression mostly at the expense of local recurrence.”