Don't panic! You have found it early and are in a great position to keep this contained.
Lymp nodes are all over your body and can be removed My mom has had several lymp nodes removed to avoid the spread of melanoma. The surgery is usually out patient and very successful in getting a clean area around the melanoma cells.
I can not stress enough to keep on top of the watch IF the test shows melenoma. Find a good dermotologist that does a full head to foot search with you. You need to watch for things to be found early as well. Scans will be used to "see inside" if there is anything to be aware of.
We have been living without impacts from melanoma in its highest stage for years now. So fight it off early and find it early.
Best wishes on your test results - should it turn out to be mel don't panic there is options!