Basal Cell Tumors in Cats

Basal cell tumors in cats are generally benign tumors that can be found anywhere on the skin of a cat’s body. Not to be confused with basal cell carcinoma, these tumors are usually benign, but it is possible for them to be malignant (cancerous).

A benign tumor is one in which the cells do not spread further than the actual site where the mass is growing. In other words, a benign lesion will not spread. However, the mass can and at times will continue to grow at its site of origin. A malignant mass, on the other hand, is one in which the cancer cells can break off from the original tumor site and grow in another location such as the lymph nodes, liver or lungs.

Cat owners who notice any lumps or bumps on their cat should seek an immediate veterinary consultation since only your vet will determine whether your cat’s lump or bump is benign or malignant and then recommend the best treatment options.

What Are Basal Cell Tumors in Cats?

Feline basal cell tumors are growths or masses on the skin that are typically circular or oval in shape. Usually non-cancerous, they have a firm texture though some can be ulcerated or pigmented. These growths can range in size from 1 to 10 cm (about 0.5 – 4 inches) in diameter and can appear anywhere on the cat’s body. They most commonly are found around the upper body including the head, neck and shoulders.

What Causes Basal Cell Tumors in Cats?

The exact cause of basal cell tumors is unknown, but scientists hypothesize that environmental factors may play a role. Exposure to sunlight, certain chemicals, toxins or viruses may increase a cat’s risk for developing basal cell tumors. Genetics may also predispose some cats to developing these benign tumors. Other factors that may increase the risk of developing basal cell tumors include the cat’s age and breed. Persians, Himalayans and domestic long-haired cats have a higher tendency of developing basal cell tumors as do senior cats.

Signs and Symptoms of Basal Cell Tumors in Cats

The primary symptom of basal cell tumors is an obvious lump or mass on your cat’s skin. The mass is sometimes slightly movable and may be ulcerated due to inflammation or infection. Other symptoms of feline basal cell tumors include:

  • Lump or bump on the skin anywhere on the skin of the body
  • Round and/or raised in appearance
  • Size ranges from 1-10 cm (0.5-4 inches)
  • Skin may appear pigmented or ulcerated
  • Itching at tumor site (your cat may scratch at it)
  • Loss of hair at tumor site

While these tumors aren’t usually cancerous (malignant), they do tend to grow. They can become uncomfortable for your cat and more difficult to remove the larger they become. Therefore, it’s important to take your cat to the vet for a conclusive diagnosis.

How Are Basal Cell Tumors in Cats Diagnosed And Staged?

Since basal cell tumors are quite common among cats, diagnosis is fairly straightforward. Your veterinarian will test the tumor to determine if it is benign or malignant usually through either a cytological exam or biopsy.

  • A cytological examination is a procedure which involves removing some cells from the tumor through fine needle aspiration (FNA). While FNA is less invasive, it doesn’t always produce conclusive results. When results are uncertain, a biopsy may be performed.
  • A biopsy involves removing a tissue sample from the tumor and having a pathologist conduct a microscopic examination to determine if the tumor is benign or malignant.

If the tumor is malignant, it will be staged to determine how extensive the cancer is in the body. Blood work (CBC, chemistry profile, urinalysis), three-view chest x-rays and abdominal ultrasound may be ordered by your veterinarian.

How Do Basal Cell Tumors In Cats Progress?

Basal cell tumors in cats are usually slow-growing. And while most are non-cancerous, there is a small percentage that are malignant. If the tumor is benign and small, a “wait and see” approach may be recommended. If a “wait and see” approach is chosen, it will be important for both you and your veterinarian to periodically evaluate the mass for any growth or changes. If the tumor begins to grow, becomes ulcerated or bothersome to your cat (itching, scratching at the tumor site), treatment should be considered – usually involving surgical removal.

The small percentage of feline basal cell tumors that are malignant are referred to as basal cell carcinoma. And while this cancer doesn’t typically spread to a cat’s internal organs, it can metastasize (spread) to the lymph nodes and/or lungs, posing a risk to your cat’s life. Therefore, it’s important to have malignant basal cell tumors treated promptly. When caught early and treated appropriately, the prognosis is usually very good.

Treatment Options For Cats With Basal Cell Tumors

The exact treatment options for your cat’s basal cell tumor will depend on your cat’s overall health as well as:

  • Tumor size
  • Location and
  • Malignancy status (whether or not it is benign or malignant)

Benign tumors can be left alone if they are small and not bothersome to your cat. If the tumor grows or becomes uncomfortable, surgical removal is usually recommended. For small tumors, cryosurgery, which involves freezing of the tumor, may be an option as well. For very large tumors or tumors that are too difficult to remove surgically, radiation therapy may be a good option.

Basal Cell Carcinoma (Malignant Basal Cell Tumor)

If your cat’s tumor is malignant (basal cell carcinoma), more aggressive treatment may be necessary. Many times a combination of therapies are utilized for malignant tumors to achieve the best results including:

  • Traditional surgery
  • Cryosurgery (freezing)
  • Radiation therapy
  • Chemotherapy

Even if surgery is the primary method used to remove the malignant tumor, other cancer treatments may be utilized to ensure cancer cells in surrounding tissues and areas of the body are eliminated so that they don’t pose a future risk to your cat. Partnering with your vet, coupled with early treatment, will give your cat the best chance of making a full recovery.

Prognosis For Cats With Basal Cell Tumors

The prognosis for benign basal cell tumors in cats is generally excellent when caught early and managed properly. Benign tumors usually pose a limited risk to your pet’s well-being. Malignant basal cell tumors (feline basal cell carcinoma) also can have a very good prognosis. The earlier you catch the tumor and begin treating it, the better chance your cat has of making a full recovery. If your cat has been diagnosed with basal cell carcinoma, read our article about this malignant form of basal cell tumors.

Basal cell tumors in cats are exceedingly common. If you notice any lumps or bumps on your cat, make an appointment with your vet to get a definitive diagnosis and possible treatment options. If you have any questions about skin tumors in cats, feel free to reach out to our Pet Advocate Team at 866-461-9320. Our Pet Advocates are trained professionals who are prepared to answer any questions you might have.

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