Small Renal Masses

Publication Date: January 17, 2017

Key Points

Key Points

ASCO defines small renal masses (SRMs) as incidentally image-detected, contrast-enhancing renal tumors ≤4 cm in diameter that are usually consistent with stage T1a renal cell carcinoma.

On rare occasions, SRMs may be unusual malignant tumor types such as lymphoma, sarcoma, or a metastasis to the kidney.

More than one imaging modality may be required to confirm that the lesion is solid and/or enhancing.

With more widespread use of axial imaging, usually ordered for nonspecific gastrointestinal or musculoskeletal symptoms, there has been a continued increase in the rate of incidentally detected SRMs.

As many as 25% of SRMs are benign renal cortical tumors (eg, oncocytoma, metanephric adenoma, and angiomyolipoma), and another 25% are indolent in nature with limited metastatic potential (eg, chromophobe, type 1 papillary renal cancer).
  • Although certain renal tumor histologies have distinct imaging characteristics, current radiologic imaging cannot reliably discriminate benign from indolent or potentially malignant tumors. In addition to the diagnostic dilemma, the natural history of these lesions is variable, and many tumors demonstrate an indolent course.

Diagnosis

...iagnosi...

...basis of tumor-specific findings and competing ri...


...urveillance should be an initial mana...


Treatment

Treatme...

...rectomy (PN) for SRMs is the standard tre...


...thermal ablation should be considered an opti...


...ctomy for SRMs should be reserved on...


...al to a nephrologist should be considered if...


Figure 1. Management of Small Renal Masses

...re 1. Management of Small Rena...