Sweat duct tumors, fat grains and flat warts are all benign. 1. Sweat duct tumor belongs to benign skin tumors, which is a kind of adenoma differentiated from the ducts at the end of small sweat glands. It is mostly found in young women, often symmetrically distributed around the eyelids, but also in the forehead, cheeks, neck, abdomen and female genitalia. The lesions are skin color, yellowish or tawny hemispherical or flat papules, 1~3mm in diameter, dense and not fused, the disease is chronic and rarely subsides on its own. 2. Fatty grains, i.e., cornu rashes, are benign skin tumors, which are retention cysts originating from the epidermis or epithelium of the appendages. The typical lesion is a yellowish-white, solid, globular papule with smooth surface, rounded tip, no fusion, covered with very thin epidermis, which can be extruded into solid keratin-like globular particles. The skin lesion development is slow, can last for many years, occasionally can be natural shedding disappeared. 3. Flat warts are a benign growth caused by human papillomas infecting the skin and mucous membranes, mostly caused by HPV-3. The actual skin is usually a flat, elevated papule of rice grain to soybean size, with a smooth, hard surface, normal skin color or light brown. The course of the disease is chronic, with the highest rate of natural regression among all clinical types of HPV infection, and a few patients may have recurrence. If you suffer from the above diseases, you should go to the hospital for consultation and regular treatment under the guidance of the doctor, and should not squeeze or use medication on your own to avoid adverse consequences.