Small Renal Masses: Challenges for the Radiologist.
Radiology. 2018 Jul;288(1):91-92. doi: 10.1148/radiol.2018180602. Epub 2018 May 8. Soulen MC1.
Imagine, if you will, the following conversation between a patient and his or her radiologist:
Patient: Is it cancer?
Radiologist: I don’t know.
Patient: If so, does it need to be treated?
Patient: If so, how should it be treated?
Radiologist: I can treat you.
Patient: If so, how often and for how long will surveillance be done?
Radiologist: Let’s see how it goes.
Small renal masses are often detected as incidental findings in older patients, typically among those aged at least 65 years. The first question for the radiologist is, which ones are cancer? In a review of 2770 resected solid renal masses, 376 (12.8%) were benign (1). The likelihood of benignity is inversely related to size. One-quarter of masses smaller than 3 cm, one-third of those smaller than 2 cm, and 45% of those smaller than 1 cm are benign. Another review of 2675 resected renal masses found that 139 of 776 (18%) of tumors smaller than 3 cm were benign (2). In current practice, 129 of 916 (14%) of resected tumors prove to be benign (3).