If your doctor says you should get a lymph node biopsy, it's because they need to check for signs of disease, such as cancer. They take out a small piece of one of your lymph nodes and sends it to a specialist, who will look at it under a microscope.
Lymph nodes are parts of your body that most folks aren't even aware they've got. There are hundreds of these small organs spread around inside you, and they play a key role in filtering out harmful things, including germs.
A lymph node biopsy can help diagnose cancer or see if it's gone to another area. It can also look for infections that can explain why you have certain symptoms, such as swollen lymph nodes.