In general, three are three main types of cancer that develop from skin cells (keratinocytes): melanoma, squamous cell carcinoma, basal cell carcinoma. They differ from one another only by characteristics and prognosis. Some promptly develop to serious complications, while other types slowly grow and respond well to treatment in most cases.
Basal cell carcinoma is a cancer of the skin that responds favorably to treatment and that barely causes metastases, spreading of the cancer to other parts of the body. Despite there are other form of skin malignancy, squamous cell carcinoma and malignant melanoma, it is the most common cancer in the United States and its incidence appears to be increasing. The tumor particularly affects blond or red skin individuals, and risk increases with prolonged or regular exposure to sunlight and ultraviolet radiation.
Basal cell carcinoma usually affects people aged 60 or over, and grows from the outermost layer of the skin (keratinocytes), in the deep part of the epidermis. The cancer develops and localizes mostly on the face (eyes, lips, forehead …), scalp and neck. However, in spite of easy visibility, the diagnosis is confirmed with a biopsy followed by histological examination.
Basal cell carcinoma develops slowly and does not cause metastases. It may take different aspects like a trivial painless skin lesion, slightly raised (slightly raised flat-topped lesion for instance), often reddish in color. It can also take a similar form to that of eczema or a scar.
In addition, the cancer can take many forms, which can differ from one patient to another. Please see basal cell carcinoma symptoms for more information.
Generally, basal-cell carcinomas are divided into many subtypes, named depending on theanatomy of cells or tissues affected:
- Nodular basal-cell carcinoma– this is one of the most common forms of classic basal-cell carcinoma which tends to occur on the sun-exposed areas of the body, mainly head and neck.
- Cystic basal-cell carcinoma – this type of tumor has a dome-shaped, and characterized by blue-gray cystic nodules. It can develop on any sun-exposed area of the body.
- Cicatricial basal-cell carcinoma– this cancer tends to be aggressive and causes serious scars. It is also known as morpheaform basal-cell carcinoma, and characterized by distinct clinical and histologic appearance.
- Infiltrative basal-cell carcinoma– this is another aggressive form of skin cancer andcauses deep painful lesions, which can take different shapes.
- Micronodular basal-cell carcinoma – this form of cancer causes a micronodular growthto form under the skin. The nodulemay be painful.
- Superficial basal-cell carcinoma, also known as “superficial multicentric basal-cell carcinoma”, this tumor tends to develop on the trunk and characterize by a red patch on the skin.
- Pigmented basal-cell carcinoma – this cancer leads to an abnormal increase in the concentration of melanin in the melanocytes. It is very rare in white people (about 20%) and common among the Chinese (up to 80%).
- Rodent ulcer – this is a form of nodular basal cell carcinoma which causes the appearance of large skin lesion with central necrosis. The cancer is also called “Jacobi ulcer”.