CONDITION
Squamous Cell Carcinoma of the Pinna in Cats
Squamous cell carcinoma of the pinna is a form of skin cancer that arises in the thin, flat cells lining the surface of the ear flap. In cats, this tends to occur in areas where sun exposure has damaged the skin over time, particularly in animals with white or pale ears. The condition develops slowly, often beginning as persistent roughness, redness, or small crusted areas that may come and go before progressing to open sores or thickened patches that do not heal. Owners often notice changes that initially resemble minor injuries or irritation—small scabs, recurring scratches, or areas that bleed easily when touched. These signs may be present for weeks or months before the pattern becomes clear. Because the changes can be subtle at first, and because ear tips are naturally exposed and occasionally injured, it is not always obvious when something more persistent is unfolding. This page explores what squamous cell carcinoma of the pinna can look like in its early and later stages, what is happening in the skin as the condition develops, how veterinary surgeons investigate and confirm the diagnosis, and what approaches exist for managing it. The aim is to help orient you to the condition and the questions that may arise as you and your veterinary team work through what is happening.
Why this matters now
This condition tends to appear in older cats, often those aged ten years or more, and is strongly associated with cumulative sun exposure over a lifetime. White-eared cats and those with pale or non-pigmented ear tips are particularly vulnerable, as melanin—the pigment that offers some protection against ultraviolet damage—is sparse or absent in these areas. Cats who spend significant time outdoors, particularly in sunny climates or at higher altitudes where UV intensity is greater, accumulate the kind of repetitive cellular damage that can eventually give rise to squamous cell carcinoma.
The condition typically develops slowly, often over months to years. Early changes may be subtle and intermittent—areas of redness or crusting that seem to improve and then return—before becoming more persistent and visibly abnormal. In some cases, the progression remains localised to a small area of the pinna for an extended period, whilst in others the tissue changes spread more broadly across the ear tip or involve both ears. The timeframe and pattern can vary considerably between individual animals.
Signals & patterns
Early signals
Persistent roughness or scaling
The skin on the ear tip may feel slightly thickened or rough to the touch, with fine scaling that does not resolve. This can resemble dry skin or mild irritation, but it tends to recur in the same spot even after seeming to settle.
Small crusts that reform
A crust or scab may appear, fall off or be scratched away, and then reappear in the same location. The cycle of crusting and shedding can continue for weeks, and the area beneath may look pink or raw.
Localised redness or pink patches
A patch of skin on the ear margin may appear pinker than the surrounding tissue, sometimes with a slightly shiny or taut surface. This redness may come and go initially, but over time it tends to become more constant.
Bleeding with minor contact
The affected area may bleed easily when the cat shakes its head, scratches, or when the ear is gently touched. The bleeding is often minor but recurs readily, and the tissue may seem fragile or prone to breaking down.
Later signals
Open sores or ulcers
The skin may break down into an open sore that does not heal, often with irregular edges and a moist or raw surface. The ulcer may gradually enlarge or deepen, and secondary infection can cause odour or discharge.
Thickened or nodular tissue
The affected area may become noticeably thickened, raised, or nodular, sometimes with a cauliflower-like texture. The normal shape of the ear tip may be distorted, and the tissue can feel firm or irregular beneath the surface.
Loss of ear-tip architecture
As the tumour progresses, the edge of the pinna may become eroded or deformed, with tissue loss that alters the silhouette of the ear. In some cases, the tip may curl or contract as healthy tissue is replaced by abnormal growth.
Click to read about the biological mechanisms
How this is usually investigated
Options & trade-offs
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