When deer hunters are field dressing and butchering their harvested animals, there are 2 normal anatomical structures that are commonly seen and often cause concern for the hunter. These 2 structures are lymph nodes and hemal nodes (or hemolymph nodes).

Lymph nodes occur throughout the body but the one most commonly seen and submitted is the subscapular lymph node that is usually located in a mass of fat behind the shoulder blade. Lymph nodes are normally gray, yellowish brown, or tan in color, oval in shape, and appear slimy. Lymph nodes have the general appearance of a raw oyster. It is not uncommon for a hunter to have killed and butchered several deer in his/her lifetime and never to have seen a lymph node. Because of this, it does cause concern in these individuals when they do cut across a lymph node, and it is at that time they often submit tissues for examination.

 Hemal nodes usually occur in the fat that lies along the vertebrae of the neck, near where the trachea is found. Hemal nodes may also occur in the abdominal cavity in the fat located along the vertebrae near the tenderloins. These nodes are numerous in ruminants (deer, elk, cattle, sheep), occur in small numbers in canids (dogs, coyotes, wolves), and are absent in many other animal species. Hemal nodes are usually ovoid (being larger than a pea), maroon or black in color, and may be either solid or fluid-filled. They resemble a very small spleen or blood clot, and are also called accessory spleens. Hemal nodes are very prominent and, as a result, many hunters see them, are concerned that they are diseased tissue, and submit samples for examination.

Both lymph and hemal nodes are filtering organs that are closely associated with the circulatory system. Abscesses have been observed in lymph nodes but have not been seen in hemal nodes. Abscesses are encapsulated pockets of purulent material (pus) that form due to bacterial invasions. (See the chapter on abscesses for complete information.)