Fine needle aspirational biopsy. It's pretty accurate, like 98% in some cases, or more, usually done with ultra sound guidance, and had about 6 of them on my lymph nodes to diagnose cancer. Anytime I found a lump, I went to the pathologist to have it done, but some ENT's doing it too, but the pathologist can take the sample slide, and view it under a microscope, and can tell if its cancerous or not, but they still send it our for further pathology, confirmation.
Waiting is the worst. Good luck,