Look for hard, red knots or wounds with a scaly/flaky edge. It usually develops in areas of the body that are exposed and damaged by the sun, but it can occur anywhere, even in the oral cavity and under clothing.
Treatment depends on the type of lesion, size, location and how deep in the skin it is located. In addition to the patient's age and general state of health are crucial. Mohs' surgery is the gold standard, but scraping and cryotherapy may be sufficient for the most superficial lesions. Treatment is mostly outpatient with local anaesthesia, and causes minimal discomfort.
The vast majority are cured, but it is important to make the diagnosis and start treatment early.