Non-cancerous growth. Benign means non-cancerous, and neoplasm means new growth. So you have a growth on your kidney that is not cancerous. If this was diagnosed by an imaging test (cat scan), you might need a biopsy in the future. You might need follow-up scans. But a benign neoplasm does not need to come out, unless it grows over time. And no, it won't take over your kidney! (now hopefully you can sleep tonight!).