Many cases of cancer are discovered when a cat’s owner or veterinarian feels or sees a lump or bump somewhere on or inside of the cat’s body. Visible skin masses can occur anywhere on a cat’s body but most often show up on the face, nose, lips, mouth (gums and tongue), head, ear tips, back of the torso and/or legs. The most common internal tumors that can be felt (palpated) are those that involve lymph nodes located either under the cat’s front “armpits” or in the groin area near the inner thighs of its hind legs. The other way that cancer is often detected is when a cat is taken to the veterinarian because of a slow, steady decline in its overall health, body condition and energy level, for no apparent reason.
A veterinarian who sees a cat with obvious abnormal masses will probably recommend taking a biopsy sample to see what the lump is made of. In many if not most cases, the veterinarian will remove the entire mass rather than only just part of it, trying to get clean surgical margins of healthy tissue all the way around the tumor. The removed tissue will be sent to a laboratory for evaluation by a skilled veterinary pathologist. Sometimes, the doctor will take a sample of the mass using a technique called a fine needle aspirate, or FNA. This involves sticking a sterile needle into the lump and drawing cells and fluid into an attached syringe. The sample will be expressed onto a sterile glass slide and assessed under a microscope. If the cat doesn’t have obvious superficial lumps or enlarged lymph nodes but is just not feeling or acting well, the veterinarian will take blood and urine samples to check how the animal’s key organs are functioning. She probably will also run blood tests for feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV). These are relatively simple and inexpensive tests that can be performed at any local veterinary clinic.
Radiographs (X-rays) of a cat’s chest are helpful to determine whether any type of cancer has spread to the lungs. If the cat is limping or has painful swollen joints, radiographs can help identify bony abnormalities. Advanced imaging techniques, such as ultrasound, magnetic resonance imaging (MRI) and computerized axial tomography (CAT) scans, are available at veterinary teaching hospitals and some specialized private veterinary practices. These can be used to identify internal masses.
The results of these diagnostic procedures will guide the medical team’s treatment suggestions and protocols. The laboratory report from the pathology laboratory evaluating biopsy samples is probably the single-most important piece of diagnostic information.