Skin cancer often develops gradually, rather than appearing abruptly. While a new spot or change might seem sudden, underlying cellular changes typically occur over time. Understanding its progression and recognizing concerning signs are important for early detection, which allows for timely intervention and improved treatment outcomes.
How Skin Cancer Typically Develops
Skin cancer originates when skin cells experience DNA changes, often due to ultraviolet (UV) radiation from sun exposure or tanning beds. This damage leads to mutations that alter cell growth and division. While the body normally repairs damaged DNA, extensive damage or failed repair mechanisms can cause mutated cells to multiply uncontrollably, forming a tumor.
Basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), the most common skin cancers, usually develop slowly over months or years. BCCs, the most prevalent type, often grow gradually and may go unnoticed because they are typically painless and can resemble benign skin conditions. SCCs also develop slowly, sometimes appearing as scaly, crusty patches that gradually enlarge.
Melanoma, a more aggressive form of skin cancer, can develop differently. While some arise from existing moles, a significant portion (70-80%) appear as new spots on previously normal skin. Though melanoma can appear suddenly and change rapidly, it may also go unnoticed for months or years, especially in less visible areas. The impression of a “sudden” appearance often occurs when a previously unnoticed lesion grows to a visible size, or when an existing lesion undergoes rapid, noticeable changes.
Identifying Concerning Skin Changes
Recognizing visual cues on the skin is important for detecting potential skin cancers. For melanoma, the ABCDE rule is a widely used guide highlighting specific characteristics to observe. “A” is for Asymmetry: one half of the spot does not match the other. “B” is for Border irregularity: edges are often uneven, notched, or poorly defined. “C” is for Color variation: inconsistent coloring, with different shades of tan, brown, black, white, red, or blue. “D” is for Diameter: typically larger than 6 millimeters when diagnosed, though they can be smaller. “E” is for Evolving: the mole or spot is changing in size, shape, color, or texture, or begins to itch or bleed.
Basal cell carcinoma often presents as a shiny, pearly, or waxy bump, sometimes with visible blood vessels, or as a flat, flesh-colored to brown, scar-like lesion. It can also appear as pink growths with raised edges or reddish, itchy patches. Squamous cell carcinoma typically manifests as a firm, red nodule, or a flat lesion with a scaly, crusted surface that may bleed.
When to Consult a Dermatologist
Consult a dermatologist promptly for any new or existing mole, spot, or growth that changes in size, shape, color, or texture. Professional evaluation is also recommended if a lesion starts to itch, bleed, or become tender. These changes can be signs of skin cancer, and early detection is important for successful treatment.
Regular self-skin exams help individuals become familiar with their skin and identify suspicious changes. For those with higher risk factors, such as extensive sun exposure or a family history of skin cancer, professional skin checks are particularly beneficial. A dermatologist can provide a thorough examination and determine next steps if a concerning lesion is identified.