Squamous Cell Carcinoma of the Skin in Leopard Geckos

Squamous cell carcinoma, often shortened to SCC, is a malignant tumor that starts in squamous cells, the flat cells that make up the outer layers of the skin. In reptiles, skin tumors are being recognized more often as captive animals live longer, and cancer should be part of the differential list for adult reptiles with persistent masses or abnormal skin lesions.

In a leopard gecko, SCC may appear as a rough plaque, scab-like area, ulcer, thickened patch of skin, or a lump that does not heal normally. Some lesions are slow-growing at first, which can make them easy to mistake for retained shed, a healing wound, dermatitis, or a burn. Over time, though, the area may enlarge, become more invasive, or recur after seeming to improve.

This cancer is often locally invasive, meaning it can destroy nearby skin and underlying tissue even if it has not spread elsewhere. That is why a lesion that looks small on the surface can still be medically important. Your vet may recommend biopsy sooner rather than later if the lesion is persistent, irregular, or worsening.

There is no single confirmed cause of skin SCC in leopard geckos. In reptiles as a group, cancer risk appears to rise with age, and some tumors may be linked to chronic irritation, prior tissue damage, infectious agents, or environmental factors. Published reptile literature has also reported papillomavirus DNA in some cutaneous squamous cell carcinomas, which suggests that viruses may play a role in at least some cases.

For skin tumors in lizards, researchers have also suggested that artificial ultraviolet lighting may contribute to skin tumor development in some species, although this has not been proven specifically for every leopard gecko case. Leopard geckos are crepuscular and do not need intense basking-style UV exposure like some desert lizards, so inappropriate lighting setups, repeated skin injury, or chronic burns are reasonable husbandry concerns for your vet to review.

Long-standing wounds, repeated retained shed in one area, chronic inflammation, and untreated skin infections may not directly cause SCC in every case, but they can make abnormal tissue harder to recognize and may contribute to ongoing cellular damage. That is one reason your vet will usually ask detailed questions about enclosure temperatures, heat source type, lighting, humidity, supplements, substrate, and how long the lesion has been present.

Diagnosis starts with a full physical exam and a close look at the lesion. Your vet will often review husbandry at the same visit because burns, dysecdysis, infection, and nutritional problems can mimic or complicate skin tumors. Photos showing how the lesion has changed over time can be very helpful.

A biopsy with histopathology is usually the key test for confirming SCC. In reptiles, Merck notes that surgical or endoscopic biopsies are preferred for diagnosing neoplasia, and histopathology helps identify the tumor type and whether the tissue looks completely removed. Depending on the lesion, your vet may take a small sample first or remove the whole mass if that is feasible.

Your vet may also recommend staging tests before surgery or after diagnosis. These can include bloodwork, radiographs, ultrasound, or advanced imaging such as CT to look for deeper invasion or spread and to help with surgical planning. If infection is present, culture or cytology may be added, but those tests do not replace biopsy when cancer is a concern.

Not every case of SCC can be prevented, but good husbandry may lower the risk of chronic skin damage and help you catch problems earlier. Focus on safe heating, appropriate enclosure temperatures, proper hides, clean surfaces, and humidity support that allows normal shedding. Avoid heat rocks and poorly controlled heat sources that can cause repeated burns.

Check your gecko's skin during routine handling and after sheds. A lesion that keeps returning in the same place, especially if it becomes crusty, raised, or ulcerated, should not be written off as "just a bad shed." Early veterinary evaluation gives your vet more options and may allow a smaller, more manageable surgery.

It is also wise to review your lighting setup with your vet, especially if you use UVB. While leopard geckos can benefit from carefully selected, species-appropriate lighting, excessive or poorly positioned UV exposure may contribute to skin problems in some reptiles. Regular wellness visits with your vet can help catch husbandry issues, subtle skin changes, and age-related disease before they become harder to manage.