A mammary gland tumor, a lump in the mammary glands, occurs mainly in the aging animals. These nodules can be benign (adenoma, 70%) or malignant (adenocarcinoma, 30%). Sterilization of the animal can have a protective effect. Clinically it is not possible to say with 100% certainty whether the tumor is benign or malignant. Benign tumors often feel like hard, well-defined nodules. Malignant tumors are usually less well defined because they grow in the surrounding tissues. They have a strong tendency to spread to the regional lymph nodes and lungs. The only way is to take a biopsy and have it examined. If malignant cells are then found, the tumor must be removed with milk gland package(s) and regional lymph nodes.
A carcinoma can also occur in other places in or on the body. They often occur in the bladder (neck) in the anal sacs and all kinds of internal organs, such as the liver, spleen, and stomach. Also, in white cats, we often see them in the skin of the ears and on the muzzle (squamous carcinoma). They are very malignant tumors, which spread quickly.