Basic knowledge about basal cell carcinoma of the skin

Basal cell carcinoma of the skin, also known as basal cell epithelioma, is common in elderly people aged 50 to 60 years old, slightly more common in men than in women. The most common sites are exposed areas with thin epidermis, rich sebaceous glands and frequent sunlight, such as the wings of the nose, inner and outer canthus, forehead, temples, neck, etc. Cancer lesions occur in the trunk, accounting for only about 10%.

In the early stage of skin basal cell carcinoma, there are single, slightly raised, light yellow or pink nodules with smooth surface, dilated capillaries, hard texture, and usually no pain or tenderness. If the lesion is located in the deeper part, after a long period of development, the surface will show scaly desquamation, followed by repeated scabs and desquamation, erosion and bleeding on the surface. When the lesion continues to grow, a superficial ulcer will form in the center, with jagged edges that look like worms. The disease progresses slowly and is not likely to metastasize to distant lymph nodes.

Some basal cell carcinomas are accompanied by melanin deposition. These small dots of pigment are spread in the lesions and merge with each other to appear brown, black or blue. They are called pigmented basal cell carcinomas, which are easily confused with malignant melanomas. However, they can be distinguished from melanomas due to their long course, slow development, and often no regional lymph node metastasis. Another relatively rare type of morphea-like basal cell carcinoma is more common in the trunk. The skin lesions are smooth fibrous plaques that resemble scar tissue. There are no obvious changes such as capillary dilation, ulcers or protrusions on the surface. The boundaries are unclear and it is easy to have extensive infiltration.