Skin Lumps, Growths and Tumours in Cats
Skin lumps, growths and tumours in cats are less common than in dogs, but can vary in appearance and behaviour and are more likely to be clinically significant, making early assessment important. While some lesions are benign, others may represent more serious or progressive conditions, and visual appearance alone is not always sufficient to determine their nature. In cats, some tumour types can behave more aggressively, meaning earlier assessment and intervention may improve outcomes.
Skin lumps and growths are often initially assessed and managed by your primary care veterinarian, who can begin investigation and treatment. If your cat’s lump is changing, firm, ulcerated, recurrent, or not responding as expected, referral for veterinary dermatology assessment can help determine what further investigation or management may be required.
What Causes Skin Lumps and Growths in Cats?
Skin lumps in cats may arise from a range of different processes, including benign growths, cysts, inflammation, infection or neoplasia, which means tumour-related disease. These lesions can develop from different tissues within the skin, including connective tissue, glands and immune cells, and may vary in behaviour from stable and non-progressive to more aggressive or invasive.
Common types of skin lumps in cats include:
Benign growths or lesions
- Cysts or benign proliferative lesions
Inflammatory or reactive lesions
- Abscesses, often associated with bite wounds or infection
- Localised inflammatory reactions, including injection-site reactions
- Eosinophilic granuloma complex lesions, which may appear as raised, ulcerated or plaque-like areas
Neoplastic (tumour-related) conditions
- Soft tissue sarcomas, including injection-site sarcomas
- Mast cell tumours
- Squamous cell carcinoma, particularly in sun-exposed areas
- Other benign or malignant tumours
The appearance of a lump alone is not always sufficient to determine its nature, and different types of lesions can look similar on visual examination.
Signs Associated with Skin Lumps and Growths in Cats
Skin lumps in cats may vary in size, shape, texture and behaviour over time, and may be present before being easily noticed. Some are found during grooming, patting or a routine veterinary examination, while others become more obvious because they change, irritate the skin, or fail to heal as expected.
Signs associated with skin lumps and growths may include:
- a new lump or swelling beneath or within the skin
- a lump that is growing, changing shape or becoming firmer
- a raised, thickened or irregular area of skin
- Scabs, sores, ulceration or breakdown of the skin surface
- a lesion that is slow to heal or repeatedly returns
- licking, irritation or discomfort focused on one area
- Localised hair loss or coat change around the affected area
- Rapid growth or progression of a lesion
These features do not always mean a lump is serious, but changes such as rapid growth, firmness, ulceration, bleeding or poor healing may indicate the need for more urgent veterinary assessment.
Why Early Assessment of Skin Lumps Is Important
While some skin lumps in cats are benign, it is often not possible to determine the nature of a lesion based on appearance alone.
In cats, early assessment is particularly important because:
- Some tumour types may be more aggressive or progressive
- Earlier diagnosis allows for more effective treatment options
- Delays may allow lesions to increase in size or become more difficult to manage
Early assessment supports appropriate investigation, diagnosis, monitoring and treatment planning.
How We Diagnose Skin Lumps and Growths in Cats
A structured diagnostic approach is used to assess skin lumps and growths in cats and determine their nature. Where referral is appropriate, your cat’s assessment begins with a dermatology consultation, where our clinician reviews their history and examines the lesion, including its size, location, appearance and behaviour over time. From here, our clinicians tailor a targeted diagnostic approach to your cat’s individual presentation.
A tailored diagnostic approach may include:
- Cytology and Fine-Needle Aspirates – a minimally invasive test used to collect cells from a lump to help determine its nature.
- Biopsy and Dermatopathology – recommended in selected cases to obtain a tissue sample for more detailed evaluation and definitive diagnosis.
- Monitoring and serial assessment – used in selected cases where lesions are stable and appear consistent with benign change
Each step helps ensure that management decisions are based on an accurate diagnosis, rather than appearance alone.
How Skin Lumps and Growths in Cats Are Managed
Management depends on the type of lesion, its behaviour over time, and your cat’s individual circumstances. Not all lumps require immediate treatment, but appropriate assessment is important to guide decision-making.
Depending on the diagnosis, management may include:
- Monitoring of stable, benign lesions, where appropriate
- Surgical removal, particularly for lesions that are changing, concerning or confirmed to be neoplastic
- CO₂ laser surgery in selected cases, where precision, reduced bleeding or improved comfort may be beneficial
- Further investigation or staging in selected cases
- Management of associated inflammation or secondary changes
The goal is to ensure that each lesion is accurately characterised, allowing management to be appropriate, timely and tailored to your cat.
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Take the Next Step for Your Pet’s Care
If you have noticed a new lump, a lump that is changing, or an area of skin that is ulcerated, scabbed, bleeding or not healing, it is important to have it assessed. A dermatology consultation allows us to examine the lesion in detail, determine whether sampling or biopsy is recommended, and distinguish between benign and more significant conditions.
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