4 diseases need to be differentiated from skin cancer

Skin cancer is one of the most common cancers. Its onset is related to excessive sun exposure, radiation damage, etc. It can occur in any part of the body. To obtain a correct diagnosis of skin cancer, it must first be differentiated from similar skin diseases.

1. Carcinoma in situ of the skin

It manifests as light red or dark red slightly raised skin lesions with many desquamations and scabs on the surface. The lesions gradually expand to become round or annular papules with clear edges, covered with brown or gray thick scabs, which are not easy to fall off. If forcibly peeled off, fine granular or fine papillary moist surfaces are revealed. After peeling, the surface is painful. The disease develops slowly or has no obvious changes for a long time. Sometimes the central part may disappear or form scars. Generally, no ulcers occur. 20%~30% may develop into invasive cancer.

2. Discoid lupus erythematosus

Discoid lupus erythematosus is a chronic skin-mucosal connective tissue disease that is prone to occur on the head and face skin and oral mucosa. The lesions are small papules at the beginning, gradually expanding into plaques, with surface keratin proliferation, dilated hair follicles, and keratin plugs. There are adherent scales on the surface of the lesions, and short, dense white stripes arranged radially around the mucosal lesions. Those that occur on the face are distributed in a butterfly shape, and erythrocyte sedimentation rate, rheumatoid factor, antinuclear antibodies, and tissue pathology can help identify them.

3. Keratoacanthoma

Keratoacanthoma, also known as molluscum sebum, is a proliferative lesion of the keratinized epithelium of the hair follicles. It is more common in middle-aged men and often occurs on the face, especially the cheeks and nose. The lesion is a solid hemispherical tumor standing on the skin, resembling a small nodule of light red acne, with raised edges and a crater-shaped center, containing a keratinous scab. Tumor cell blood type antigen detection is helpful for the diagnosis of this disease.

4. Paget's disease

This disease mainly occurs on the unilateral nipple and areola of women over 40 years old, and is less common in the armpits, around the mouth, and around the anus. Histopathological examination shows scattered or clustered Paget cells in the epidermis, and the diagnosis can be confirmed by seeing these cells. This disease develops slowly and requires drug treatment. It generally has no tendency to heal on its own.