What are the skin diseases that are often confused with skin cancer?

Skin cancer is a malignant tumor that occurs on the skin, among which squamous cell carcinoma and basal cell carcinoma are the most common. So, what are the skin diseases that are often confused with skin cancer?

1. Seborrheic keratosis. It is common in men over 50 years old, and often occurs on the face, neck, chest, back and back of hands. The lesions are round or oval flat wart-like rashes that are slightly higher than the skin. They are yellow, yellowish brown or coal black in color, with clear boundaries, soft texture, slightly rough surface, and covered with oily scaly crusts. The number of rashes is uncertain.

2. Lupus erythematosus. It is common in middle-aged men and women. The lesions are small papules at the beginning, gradually expanding into plaques. They are dry in nature, with hyperkeratinized surface, dilated hair follicles, keratin plugs, atrophic spots, no ulcers, and congested edges. They are common on the face and distributed in a butterfly shape.

3. Keratoacanthoma. It is common in middle-aged men, and often occurs on the face, especially the cheeks and nose. The lesion is a solid hemispherical tumor that stands on the skin, resembling a light red acne or a nodule similar in color to the skin, with raised edges and a crater-shaped depression in the center, containing a keratinous scab.

4. Carcinoma in situ of the skin. It is common on the trunk and buttocks, and can be single or multiple. The typical lesion is a clearly demarcated scaly maculopapule that can gradually expand or merge with each other. The size of the lesion can range from a few millimeters to several centimeters. The surface is covered with scales or brown to gray hard scabs after desquamation, which are not easy to peel off.