n.an overgrowth of skin layers resulting from extended exposure to the sun

1. Actinic keratosis can be a precursor to skin cancer if left untreated.
   如果不加治療，光化性角化病可能會發(fā)展為皮膚癌。
2. The dermatologist recommended using sunscreen to prevent actinic keratoses.
   皮膚科醫(yī)生建議使用防曬霜以預(yù)防光化性角化病。