Seborrheic keratosis, also known as seborrheic warts, basal cell papilloma, commonly known as “age spots”, is a very common benign skin tumor in middle age and above, and can involve both men and women without gender differences. The course of the disease is slow and does not heal over the years, but rarely becomes cancerous. It has obvious hereditary tendency, or is related to long-term daytime expectation. If it increases suddenly, it may be a manifestation of malignant tumor, especially gastrointestinal tumor. Clinical manifestations 1. The damage occurs on the face, especially the temporal area, followed by the back of the hands, trunk and limbs. 2. Initially light brown or dark brown or black, flat papules slowly increase in size, with rough surface or papilloma-like hyperplasia, often with greasy scales and variable number. 3. Multiple seborrheic keratosis-like lesions appear within a short period of time, which may be accompanied by visceral malignant tumors. Diagnostic basis 1. Typical skin lesions with paste-like appearance at the site of predilection. 2. Histopathology: hyperkeratosis and papillomatous hyperplasia, visible angular cysts, tumor cells composed of basal-like cells. Treatment principle 1.It is benign tumor and generally does not require treatment. 2.When necessary, topical 5-Fu ointment, cryotherapy, and laser treatment are used. 3.Faster growth, obvious hyperplasia or suspicious malignancy should be treated by surgery and pathological examination. Early stage: light yellow-brown or tea-colored patches with clear boundaries and smooth surface. Mid-stage: later the lesion gradually expands and rises, the pigment deepens and becomes dark brown or black Late stage: papilloma-like hyperplasia, single or multiple.