Which condition is a premalignant precursor of squamous cell carcinoma (SCC)?

The condition that serves as a premalignant precursor to squamous cell carcinoma (SCC) is actinic keratosis. Actinic keratosis is characterized by thick, scaly patches of skin that develop due to prolonged exposure to ultraviolet (UV) radiation, typically from the sun. These lesions have the potential to progress to SCC if left untreated, which is why they are considered precursors to this type of cancer.

Actinic cheilitis, while also related to sun exposure and sometimes leading to SCC, specifically affects the lips and has a similar risk profile to actinic keratosis as a precursor to squamous cell carcinoma. However, in the context of general skin lesions leading to SCC, actinic keratosis is more commonly highlighted.

Basal cell carcinoma and melanoma are types of skin cancers, not precursors to SCC. Each of these conditions represents different pathways of skin malignancies, but they do not directly associate with the development of SCC. In summary, actinic keratosis is recognized for its direct association with SCC development, making it an important focus in dermatology for early detection and prevention strategies.