Australia has one of the highest rates of skin cancer in the world.
The outer layer of the skin contains three different types of cells: squamous cells, basal cells, and melanocytes. Skin cancers are named for the type of cell from which they arise. Hence, the three main types of skin cancer are basal cell carcinoma (commonly abbreviated as BCC), squamous cell carcinoma (SCC) and melanoma. Melanoma is the most serious and develops from the melanocytes or ‘pigment cells’.
Basal cell carcinoma
Basal cell carcinoma is the most common and least dangerous type of skin cancer; most often found on the head, neck or upper body. Basal cell carcinomas usually start as small, round or flattened lumps that are red, pale or pearly in colour, and may have blood vessels on the surface.
Squamous cell carcinoma
Squamous cell carcinoma is less common than basal cell carcinoma and potentially more dangerous. Squamous cell carcinomas grow more rapidly, may spread to nearby lymph nodes or, in rare cases, to other parts of the body if not treated relatively quickly. They occur most often on sun-exposed areas of skin. A squamous cell carcinoma looks like a thickened red scaly spot, which may bleed easily or ulcerate over time – it may also be tender to touch.
Melanoma develops from the melanocytes and can occur anywhere on the body, even in areas not exposed to the sun. Melanoma is the most deadly form of skin cancer, and if not treated, may spread to other parts of the body. They may appear as a new spot or an existing spot that changes in shape, colour or size.
Merkel cell carcinoma
Merkel cell carcinoma is a highly aggressive skin cancer. It presents most commonly on the head and neck, as a painless, flesh-coloured, red or purple nodule on sun-exposed skin. It often appears relatively innocuous, and may be dismissed initially as a benign lesion. As such, it has frequently spread when diagnosed, and has a high tendency to recur locally, in nearby lymph nodes and other organs after initial treatment.
Other rarer skin cancers include sebaceous carcinoma, eccrine carcinoma, dermatofibrosarcoma protuberans (DFSP), atypical fibroxanthoma, undifferentiated pleomorphic sarcoma (formerly malignant fibrous histiocytoma, MFH), angiosarcoma and Kaposi sarcoma.