Skin Cancer Gregory Hills
Sun Spots vs Skin Cancer: How to Tell the Difference
A new spot appears on your skin and you're not sure what to make of it. It could be a harmless sun spot that has developed over years of UV exposure, or it could be something that warrants a closer look from a medical professional.
The two aren't always easy to distinguish by sight alone, which is exactly why understanding the differences, and their limits, matters.
What Are Sun Spots?
Sun spots, also called solar lentigines or age spots, are flat, pigmented marks that develop on areas of skin with a history of sun exposure. They are very common in Australia and tend to appear on the face, hands, shoulders, and arms. As their name suggests, skin sun spots are caused by the cumulative effect of UV radiation on melanin production in the skin.
Typical features of a sun spot
- Flat and smooth to the touch, with no raised texture
- Uniformly tan, light brown, or dark brown in colour
- Well-defined edges with a consistent border
- Stable in appearance, not changing significantly over time
- Not itchy, bleeding, or crusting
Signs that need medical review
- Uneven colouring, with multiple shades of brown, black, red, or white within a single spot
- An irregular or poorly defined border
- A spot that has grown or changed shape over a period of weeks or months
- A lesion that bleeds, weeps, itches, or develops a crust
- A new spot appearing after the age of 40 on sun-exposed skin
Sun spots are benign and don't usually require treatment from a medical standpoint, though they are a visible sign of UV damage and are sometimes confused with other lesions that do require attention.
When Brown Patches on Skin Become a Concern
Not all brown patches on skin are sun spots. Several conditions can produce similar pigmentation, including seborrhoeic keratoses, freckles, and lentigo maligna, which is an early form of melanoma. The challenge is that some of these conditions look very similar to a sun spot without dermoscopic examination.
These features do not confirm a diagnosis. Only a qualified medical professional with appropriate examination tools can determine whether a lesion is benign or requires further investigation.
What Are Cancerous Sun Spots?
The term cancerous sun spots typically refers to malignant lesions that have developed in areas of chronic sun exposure. Lentigo maligna melanoma is one example, arising from a slowly spreading flat lesion that can look like an ordinary sun spot for years before it becomes invasive. Similarly, sun cancer spots such as superficial basal cell carcinomas or Bowen's disease (a form of squamous cell carcinoma in situ) can present as flat, pigmented, or scaly patches that are easy to overlook or dismiss.
Why self-monitoring for sun cancer spots has real limits
The ABCDE rule (Asymmetry, Border, Colour, Diameter, Evolving) is a useful guide for self-monitoring, but it was designed as an awareness tool, not a diagnostic one. Some early-stage malignant lesions don't yet display dramatic changes under these criteria.
A dermoscope, used by a trained clinician, reveals structural patterns in pigmented lesions that are simply not visible to the naked eye. This is the gap that a professional skin cancer assessment is designed to fill.
Not Sure? Book a Skin Check and Know for Certain
If you have a sun skin spot you're unsure about, the most useful thing you can do is have it looked at by a professional. Sun spots and skin cancer are not always distinguishable without clinical assessment, and the peace of mind that comes from a clear examination is worth more than second-guessing.
Book a skin check at Skin Cancer Gregory Hills and let our team give your skin the attention it deserves.
Dr Pedro Valente is a skin cancer doctor at Skin Cancer Gregory Hills with specialist training in plastic and reconstructive surgery and a Diploma in Skin Cancer Medicine. He holds fellowships with the Royal Australian College of General Practitioners, the Australasian College of Cosmetic Surgery, and the American Academy of Cosmetic Surgery. His clinical focus is on skin cancer detection, surgical treatment, and delivering strong cosmetic outcomes, particularly for complex or facial skin cancers. Dr Valente speaks fluent Portuguese and conversational Spanish.