These are the nodes to which testicular cancer first spreads. They can only be seen in imaging studies. Mesenteric lymph nodes lie deep within the abdomen in the membranes that surround the intestine.
A mesenteric lymph node containing SIV RNA (red dots) in this image taken with a Comb-CODEX-RNAscope. The lymph node also contains B cell zones (green) and T cell zones (blue).