Seborrheic keratosis (SK), also known as senile warts, senile plaques, and basal cell papilloma, is one of the most common benign clinical skin tumors that occurs in middle-aged and older adults over the age of 40, and is more common in older men after the age of 60. It is a benign epidermal proliferation due to keratin-forming cell hyperplasia, which occurs on the head of the face, trunk, and upper extremities, but can also occur anywhere on the body surface, but does not involve the palm or the plantar area. It has been reported that SK has a significant familial predisposition and is presumed to be an autosomal dominant disorder with an incomplete ectopic rate, but there are few statistical reports on its prevalence, gender or racial predisposition and regional distribution. The disease is more common in Caucasian populations, with equal prevalence in both sexes. Sun exposure has been reported to be associated with the development of SK. Sudden seborrheic keratosis (Leser-Trelat sign) has been found to be associated with visceral malignancies, particularly gastric adenocarcinoma. Clinical presentation: It starts as a pale brown macule or flat papule with a smooth or slightly papillomatous surface, increasing in size and number with age, 1 mm to 1 cm or several centimeters in diameter, with clear boundaries and a papillomatous surface and greasy scabs, which are easily scraped off. However, some damage pigmentation can be very prominent, dark brown or black. The color of old damage varies greatly and can be normal skin color, light brown, dark brown or black. The disease can be solitary, but is usually multiple, with no conscious symptoms and occasional itching. The lesions develop slowly and rarely become malignant. Pathological histopathology group of disease is basically characterized by outward growth, hyperkeratosis, hypertrophy of the spinous layer, papilloma-like hyperplasia, with pseudocornea cysts. In some cases, there is a majority of black granules in the proliferating keratin-forming cells. Pathological typing: keratinized (papillomatous), thickened spiny layer, nested, adenoid, and irritated type. Differential diagnosis: Some of the early damage resembles flat warts; damage occurring on exposed areas can be easily confused with solar keratosis; deeply pigmented damage needs to be differentiated from melanocytic nevi; inflammation or irritated damage can resemble basal cell carcinoma, squamous cell carcinoma or malignant melanoma, which can be differentiated by histopathological examination. Treatment: This disease does not affect the working life and generally does not require treatment. In cases where the diagnosis is not clear, histopathological examination can be done on the skin lesions. If the growth site is special and treatment is needed for cosmetic reasons, liquid nitrogen freezing, carbon dioxide laser, erbium laser, scraping or surgical excision can be used. Although benign tumor, long-term friction may cause rupture, infection, or even induce malignancy after repeated improper stimulation with medication, so timely treatment is recommended to avoid misdiagnosis.