Mr. Palazzo, a fisherman in his late 60s comes to your clinic complaining of small ulcers on his forearms, face and ears. He has had them for year, but no other problems. What is his most likely diagnosis, and what was the most likely cause?

Most likely diagnosis is Basal Cell Carcinoma (BCC), most likely caused by years of prolonged exposure to sunlight over time.

Explanation:

Basal Cell Carcinoma (BCC) is a common type of skin cancer that develops when the basal cells that is responsible for producing new skin cells when they die, become mutated and causes the basal cell to abnormally multiply rapidly and continues to grow. The accumulation of these abnormal cells is what results  in cancerous tumors that appears like ulcers on the skin. Prolong and intense exposure to the ultraviolet (UV) radiation from sunlight has been linked to the most likely cause for the mutation of the DNA in the basal cells which leads the abnormal cell growth and multiplication. People who expose themselves to the radiation of the sun for longer periods, over time, are at high risk of developing this cancer.