What Is This Skin Lump on My Cat? 

5 min read
Sep 24, 2023

A large lump appeared on your cat overnight, how panicked should you be? Well, there are many reasons why lumps and bumps appear on your cat, including the possibility of a benign condition like lipoma- let's discuss what they could be and what to do when you find them.

Skin Lumps on Cats

A lump or bump could be as simple as a bee sting or feline acne, or something more serious, like cancer. Sitting on your couch with your wiggly cat can make it very difficult to tell, so before you run to the vet, here are some of the most common bumps on cats that aren’t cancerous.


According to PetMD, a papule on a cat is the result of inflammatory cells infiltrating tissue, creating lumps or bumps beneath the skin.³ Papules are noncancerous and are a natural response to an irritant on your cat's skin. Pay attention to areas of swelling, infected hair follicles, or pus-filled bumps. Your cat probably got into something that exposed them to bacteria or nematodes (a parasitic roundworm that lives in soil).³

Chat with your vet about where your cat spends their time, like your backyard or balcony, as that could be a contributing factor. You may be able to treat these sorts of infections at home with prescriptions or over-the-counter medication.

Insect and bee stings

If your cat goes outside, they may have run into a bee, hornet, or wasp and gotten stung trying to catch it. The skin’s reaction to bug bites varies from minor to major depending on your cat’s immune system. Symptoms of a bee sting often include:⁴

●      Swelling

●      Redness

●      Itching

●      Pain

●      Hives

Call your vet if you notice these symptoms or if you find a stinger in their skin. Antihistamines and steroids are common at-home treatments. Note that if your cat shows signs of anaphylaxis, do not hesitate to take them to an emergency clinic.⁴

Cat abscesses

A cat abscess is a bubble of pus on your cat. Abscesses in cats are caused by a bite from another cat or an open wound that became infected.⁵ Abscesses may feel firm to the touch, full of fluid, and vary in shape and size. Your cat may also experience a loss of appetite, develop a fever, and become depressed.

Your vet will review your cat’s medical history before choosing to drain the abscess. Sometimes antibiotics will resolve the infection. Removing an abscess is considered surgery that can cost $200 or more depending on where you live.⁶ Without pet insurance, you will have to pay for the procedure and any antibiotics prescribed. Growths like abscesses might be covered if you already have pet insurance, so consider diving into MetLife Cat Insurance policies,2

Lumps Can Be Scary.  Vet Bills Don't Have To Be.

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 tabby cat scratching itself.

Feline acne

Acne isn’t just a human thing! If you see bumps in oily places, your cat may have pimples. Cat acne is usually on their chins, and is most common in cats with less hair to absorb the oils that can get trapped in the skin. You can typically find blackheads and raised bumps on the chin and lips. The area may be swollen from irritation and can be uncomfortable for cats if not treated.

Feline acne can be managed at home with improved hygiene, dietary changes, and lifestyle changes like more play.⁷ If left untreated, the acne can become infected and require steroids. Take your pet to the vet if the acne doesn’t resolve itself, as it may signify a larger issue such as tooth rot and autoimmune issues.⁷ 

Is This Lump on My Cat Cancer?

Cancer in pets is a sad reality. It’s even worse for cat owners because cats often hide their pain and discomfort. Because of this, cancer often isn’t detected in cats until it is untreatable. Take your cat to the vet immediately if you suspect the bump on their body is cancerous.

Fibrosarcoma in cats

Fibrosarcoma is an aggressive tumor that starts in the soft, connective tissue of the body.⁸ These types of tumors are not uncommon and can be found all over the body — including the mouth — and spine. If you find a bump that is irregular in shape and firm to the touch, contact your veterinarian immediately. These tumors can only be diagnosed through a physical examination and surgical removal, and chemotherapy will likely be necessary.⁹

Mast cell tumors in cats

Mast cell tumors are one of the most common forms of cancer in dogs and cats. Fortunately, most of these tumors are benign and aren’t aggressive. The size of the tumors can vary, so look for a lump that is firm to the touch or clustered together.10

Basal cell tumors

Basal cell tumors are the most common skin tumor in cats and dogs. These tumors can begin as benign growths but, if left untreated, can become cancerous. Look for a lump on their head, neck, or chest that is a different color than their skin — it may be a basal cell.¹¹  Press on it to see if it is full of liquid or firm. Then schedule a vet appointment immediately.

Diagnosis and Treatment Options

The route toward a diagnosis for your cat will look pretty much the same. Your vet will collect blood samples for the lab, perform a physical exam, and discuss your cat's lifestyle.³ If they believe the lump is a tumor, a biopsy will be conducted to determine if the lump is cancerous and, if so, what type of cancer it is. Biopsies help vets plan an appropriate treatment based on the severity of the tumor.¹¹

In terms of treatment, surgical removal, chemotherapy, and radiation of the tumor and surrounding area may be necessary. Amputations are reserved for worst-case scenarios, but surgery of any kind may not be necessary at all. Your vet may choose to simply monitor the tumor and advise lifestyle changes depending on how old your cat is and their overall health.

Pet Insurance for Your Cat

If you’re lucky, the bump on your cat is something that you can easily treat at home. This is the least expensive option for your family. If you receive something like a cancer diagnosis, it can potentially cost thousands. You may find that the cost of pet insurance is a small price to pay for the financial peace of mind it can bring when vet bills start adding up.

Consider adding pet insurance to your pet care toolkit to ensure you can give your cat the care they deserve. A pet insurance policy with MetLife can cover the cost of veterinary visits, including blood work, biopsies, and digital imaging.²  Let us help you keep your kitty healthy and happy for years to come.

We Can Help Cover Vet Bills
While You Focus on Your Cat’s Care

 Dr. Hunter Finn

Dr. Hunter Finn is an integrative veterinary expert first, and social media star second. America’s favorite veterinarian owns Pet Method in McKinney, Texas, where he cares for pets while prioritizing their emotional well-being. When he’s not at his clinic, he’s starring in viral videos on TikTok (2 million followers) and Instagram (500K followers) — where he’s been known to snuggle puppies and conquer the latest dance trends.

Nothing in this article should be construed as financial, legal or veterinary advice. Please consult your own advisors for questions relating to your and your pet’s specific circumstances.

¹ Pet Insurance offered by MetLife Pet Insurance Solutions LLC is underwritten by Independence American Insurance Company (“IAIC”), a Delaware insurance company, headquartered at 485 Madison Avenue, NY, NY 10022, and Metropolitan General Insurance Company (“MetGen”), a Rhode Island insurance company, headquartered at 700 Quaker Lane, Warwick, RI 02886, in those states where MetGen’s policies are available. MetLife Pet Insurance Solutions LLC is the policy administrator authorized by IAIC and MetGen to offer and administer pet insurance policies. MetLife Pet Insurance Solutions LLC was previously known as PetFirst Healthcare, LLC and in some states continues to operate under that name pending approval of its application for a name change. The entity may operate under an alternate, assumed, and/or fictitious name in certain jurisdictions as approved, including MetLife Pet Insurance Services LLC (New York and Minnesota), MetLife Pet Insurance Solutions Agency LLC (Illinois), and such other alternate, assumed, or fictitious names approved by certain jurisdictions.

² Provided all terms of the policy are met. Application is subject to underwriting review and approval. Like most insurance policies, insurance policies issued by IAIC and MetGen contain certain deductibles, co-insurance, exclusions, exceptions, reductions, limitations, and terms for keeping them in force. For costs, complete details of coverage and exclusions, and a listing of approved states, please contact MetLife Pet Insurance Solutions LLC.

³ “Skin Bumps (Papulonodular Dermatoses) Cats,” PetMD

⁴ “Cat Stung by Bee or Wasp? Here’s What to Do,” Excited Cats

⁵ “Abscesses in Cats,” VCA Animal Hospitals

⁶ “How Much Does Cat Abscess Treatment Cost?,” SpendonPet.Com

⁷ “Chin Acne in Cats,”VCA Animal Hospitals

⁸ “Fibrosarcoma in Cats,” Wag!

⁹ “Tumors of the Skin in Cats: Soft Tissue Sarcomas,” Merck Veterinary Manual

¹⁰ “Mast Cell Tumors,” Animal Medical of New City

¹¹ “Skin Basal Cell Tumors”, VCA Animal Hospitals