If i can't able to go for biopsy and ultra sound howcan i differentiate cancer and lymph?

Biopsy is best: Sometimes imaging with a pet/ct can help but ultimately tissue confirmation is really necessary to distinguish between normal vs cancer in the lymph node.

Need microscope: The definitive diagnosis of cancer can be made (with very few exceptions) only by examining the tissue in the lab, beginning with microscopy. I'm a pathologist and have done a lot of this, and it's challenging; one must be 100% accurate, and it takes most people about a year of working in the area to get even halfway good. Thankfully, pathology is several years of residency & we help each other.