Molecular testing can help doctors distinguish between aggressive and indolent kidney cancer types, explained Dr. Shuanzeng “Sam” Wei of Fox Chase Cancer Center. Subtypes like papillary renal cell carcinoma may require major surgery, while mucinous tubular spindle cell carcinoma is often less aggressive. Wei: For renal cell carcinoma diagnosis, it’s simple for carcinoma, but for the subtypes of renal cell carcinoma, sometimes it’s difficult. For example, in this study, we mentioned papillary renal cell carcinoma and mucinous tubular spindle cell carcinoma. With molecular testing, specifically looking at chromosomal losses, we correctly identified it as mucinous tubular spindle cell carcinoma.