Intestinal Lymphosarcoma is a malignant cancer often seen in older cats. The cancer will usually originate in the lymph nodes located within tissues surrounding the intestines (mesentery) or within the lymphoid cells inside the intestinal walls themselves.
The cat with intestinal lymphosarcoma may appear perfectly normal for a time, then begin to act lethargic and stop eating, lose weight, vomit and suffer from diarrhea. Eventually, your veterinarian will be able to detect a thickening of the cats intestinal walls or be able to feel large masses within the abdomen. These masses are usually cancerous lymph nodes.
Due to the difficulty in diagnosing this form of cancer in the early stages, a cat with intestinal lymphosarcoma will become more debilitated as the cancer spreads and will usually die within two to six weeks after the cancer is recognized -- if aggressive treatment is not undertaken.
Early recognition of intestinal lymphosarcoma is difficult. The cat will often have a poor hair coat, be very thin and lethargic, and is often dehydrated due to the cats inability to process the nutrients normally absorbed through the intestinal wall. The rapidly multiplying cancer cells consume most of the bodys energy leading to rapid weight loss and eventual emaciation. As the intestinal cancer progresses, diarrhea and vomiting develop with the intestine losing its ability to absorb nutrients and becoming mechanically blocked by rapidly growing tumors.
Bloodwork is generally normal, although elevations in liver and kidney enzymes can be seen if the cancer has spread to those organs. A Feline Leukemia test may be negative.
Radiographs (x-rays) can show thickening of the intestinal loops and/or small masses. However, in some cases, the radiographs can look normal. Ultrasound images can clearly show the presence of thickened intestinal loops and/or enlarged cancerous lymph nodes, making it a valuable diagnostic tool . . . second only to biopsy or needle aspiration.
Intestinal lymphosarcoma can only be confirmed with a biopsy. In a biopsy for lymphosarcoma, a section of the tumor is taken from the cats abdomen or intestinal wall and examined under the microscope by a veterinary pathologist. A diagnosis can sometimes be made by looking at cells from a needle aspiration. This is when a long needle is inserted into the suspected tumor and cells are extracted through the needle and examined microscopically. However, in some cases, the clinical signs are so consistent with lymphoma that many owners elect not to confirm the cancer via these invasive methods.
The long-term survival rates for cats with intestinal lymphosarcoma are not good. Some cases have been treated using chemotherapy. Remission rates for cats are approximately 75% and most cats stay in remission for anywhere from seven to 14 months. Without treatment, the cat will usually survive less than six weeks.
There are several chemotherapy agents used for treating intestinal lymphosarcoma; usually a combination of oral prednisone (a steroid) given daily at home with weekly intravenous (in the vein) injections of anti-cancer drugs administered by the veterinarian. In most cases, cats will tolerate the chemotherapy drugs well. However, some cats may become ill enough to require hospitalization. It is always advisable to consult with a board-certified veterinary oncologist (cancer specialist). See referral list for details.
Prognosis is poor for long-term survival. Without treatment, cats rarely live beyond two to six weeks after the development of clinical signs. With chemotherapy and/or surgery, the survival rates are longer, usually between two and six months or longer depending on the stage of the cancer when first treated.