Basal cell carcinoma is a malignant tumor that usually occurs on the skin. It arises from the basal cells of the top layer of the skin, called the epidermis, and grows very slowly. Basal cell carcinoma is the most common form of skin cancer and has a very good chance of cure if detected and treated early.

Actinic keratosis, also known as solar keratosis or senile keratosis, is a premalignant lesion of the skin caused by long-term exposure to UV radiation. It is one of the most common skin diseases, occurring mainly in middle-aged and elderly people. The disease is most common on skin areas that are most exposed to the sun, especially the face, scalp, hands, forearms and neck. Actinic keratoses are often divided into two categories: uncomplicated actinic keratoses and higher-risk actinic keratoses. Uncomplicated actinic keratoses are more common and have a lower risk of developing into invasive squamous cell carcinoma. Higher-risk actinic keratoses, on the other hand, have a higher risk of developing into squamous cell carcinoma and therefore require closer monitoring and treatment.

A melanoma is a malignant tumor that arises from pigment-forming cells (melanocytes) and usually occurs in the skin. It is the most dangerous skin cancer and can form metastases that can be life-threatening. Early detection and treatment is therefore particularly important.

Acne is a very common skin condition that occurs mainly during puberty, but can also occur in adults. It is an inflammation of the sebaceous glands and hair follicles, which can manifest itself in the form of blackheads, papules, pustules and inflammatory nodules on the skin.