NEW YORK – When a patient turned up at the Weill Cornell Medical Center a few years ago with a typically benign kidney tumor type, it did not initially set off alarm bells. The tumor didn’t seem all that threatening, and the patient was an adult, albeit somewhat younger than individuals who usually come in with that kind of tumor.

It wasn’t until that patient returned roughly six months later with a metastatic form of the disease that clinicians realized they were dealing with...