Feline Cutaneous Squamous Cell Carcinoma: Solar Dermatosis and Pinnectomy

Feline cutaneous squamous cell carcinoma (SCC) is the most common ultraviolet (UV) radiation-induced skin malignancy affecting domestic cats with white coats or sparsely-haired, non-pigmented epidermis. Characterized by a relentless clinical continuum that originates as solar actinic keratosis (erythema and scaling) and progresses into invasive, destructive ulceration, this neoplasm causes local cartilage erosion, recurrent hemorrhaging, and tissue loss primarily targeting the pinnae, nasal planum, and periocular margins.

Sources

This guide is not a substitute for a vet.24h Emergency Vets

Veterinarian performing dermatoscope examination on the sun-damaged ear tip of a white domestic cat — Foto: Nekolife

In this guide

Clinical Stages and Sun Risk

Chronic UVB exposure induces cumulative DNA photodamage within basal keratinocytes, resulting in p53 gene mutations. The classical progression encompasses:

Actinic Dermatitis (Pre-malignant): Persistent erythema, mild scaling, and thinning of hair at the ear tips or nasal bridge.
Carcinoma in Situ: Adherent crusts that bleed easily upon scratch trauma, with induration of the underlying pinnal margin.
Invasive Squamous Cell Carcinoma: Malignant, non-healing crusted ulcers that progressively invade and destroy the cartilage framework.

Treatment Protocols and Surgical Pinnectomy

Bilateral/Unilateral Pinnectomy: Total or subtotal surgical amputation of the affected pinnae with 1 to 2 cm tumor-free lateral margins provides cure rates exceeding 90% in early to moderate stages.
Cryosurgery & Photodynamic Therapy: Optimal modalities for superficial pre-invasive lesions or nasal planum involvement.
Sun Protection Guidelines: Strict indoor confinement between 10:00 and 17:00, installation of UV-blocking window tint, and veterinary-approved pet sunscreens strictly devoid of toxic zinc oxide.

Scientific Sources and References

Murphy, S. (2013). Cutaneous squamous cell carcinoma in cats. In Practice, 35(8), 434-444.
Lana, S. E., et al. (1997). Feline cutaneous squamous cell carcinoma of the pinna and the nose: 85 cases (1980-1991). Journal of the American Animal Hospital Association, 33(4), 329-332.

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