The Spot

Actinic keratoses are rough, scaly patches caused by years of sun exposure. They are not yet cancer — but they are the most common precancerous skin condition and a direct precursor to squamous cell carcinoma. Treating them is the most effective way to prevent SCC.

Atypical moles — also called dysplastic nevi — are benign. They are a marker of melanoma risk, not a step on the way to it, and most do not need to be cut out again when a biopsy margin is positive.

Basal cell carcinoma is the most common form of skin cancer in the United States, accounting for roughly 80% of all cases. It rarely spreads but can cause significant damage if left untreated — and is almost always curable when caught early.

Melanoma is the most serious form of skin cancer, developing in the cells that give skin its color. When caught early, it is highly treatable — which makes regular full-body skin checks essential.