(Disclaimer: This article is only for scientific purposes, in order to protect the privacy of patients, the relevant information in the following content has been processed) Abstract: The patient, Ms. Wang, 37 years old, reported that there was a flesh-colored lump behind her ear, which was not painful or itchy, and she felt a piece of tissue hyperplasia under the skin by touching it with her hand and it was obviously enlarged, so she came to our clinic for medical treatment. After physical examination and dermatopathologic examination, he was diagnosed as epidermoid cyst. After communication about the condition, we chose to use carbon dioxide laser to treat along the root of the epidermoid cyst in a single treatment to remove it cleanly, and the cystic mass disappeared after the treatment. Basic information] Female, 37 years old [Type of disease] Epidermoid cyst [Hospital] Harbin Hospital of Traditional Chinese Medicine [Date of consultation] May 2022 [Treatment plan] Carbon dioxide laser + medication (Lidocaine hydrochloride injection + Levofloxacin hydrochloride capsule) [Treatment period] Outpatient treatment for 7 days, followed up by phone call 14 days after the initial treatment [Result] Flesh-colored cystic mass on the surface of the skin disappeared. The patient, Ms. Wang, said that she had a small lump behind her ear one month ago, which gradually increased in size and formed a flesh-colored mass. Although there was no pain or itching, it grew on the surface of the skin and she was very worried, so she came to our clinic for consultation. On examination, the patient was seen to have a flesh-colored mass-like growth behind the right ear, with a smooth surface, and cystic changes could be felt by touching with the hand and the underside of the skin, which were fixed and immobile. Epidermoid cysts were considered based on appearance alone, but dermatopathologic examination was needed to clarify the diagnosis, and the patient agreed. Dermatopathologic findings showed that the cyst wall consisted of ridged epithelial cells lined with keratin hyaluronic protein granules, and a mixed follicular funneling outer hair root sheath could be seen. The pathologic results were consistent with the diagnosis of epidermoid cyst. Second, the treatment process According to the patient’s condition and the treatment plan for communication, the patient agreed to do carbon dioxide laser treatment, in order to one-time radical treatment. After local disinfection with iodophor disinfectant, local anesthesia was applied with lidocaine hydrochloride injection, and then carbon dioxide laser treatment was performed along the base of the epidermoid cyst in order to detach the entire epidermoid cyst from the body. A temporary pit remained in the area after treatment, and aseptic dressing was applied. The patient was instructed to take oral anti-inflammatory drug levofloxacin hydrochloride capsule to avoid infection. Third, the treatment effect 7 days after the operation, the patient carried out dermatopathological examination after the removal of stitches, see the local tissue healing is good, no redness and swelling, after the local removal of stitches, the wound is not torn, the wound site is cleaner, and then carry out the carbon dioxide for laser treatment. The patient went home and called back 7 days later, and reported that the local tissue had crusted and started to fall off, and there was no redness, swelling or pain. The patient was instructed to have a timely follow-up if there were any abnormal changes, and not to use drugs indiscriminately to prevent irritation. Fourth, precautions Glad that the patient’s epidermoid cyst was removed after laser and drug treatment. Patients need to pay attention to the fact that there will be local wounds after choosing pathological examination, and it is recommended not to get wet within 3 days to avoid local breeding of bacteria, which will lead to purulent changes. As the carbon dioxide laser treatment leaves a concave change, avoid touching directly with hands, and pay attention to not eat spicy stimulation and seafood fishy food, to avoid affecting the healing. In addition, it takes 5-10 days for the local scabs to fall off, so be patient enough and don’t snap off the scabs with your hands to avoid leaving depressed scars and affecting your appearance. Epidermoid cyst is a common benign tumor of the skin, manifested as compressible, no fluctuating cystic mass with smooth surface, which can occur in the face, neck, behind the ear, etc., as in this case. After diagnosis of epidermoid cysts, it is important to avoid rupture to avoid localized foreign body inflammatory reaction, resulting in redness, swelling, pain and other adverse symptoms. Patients can choose to completely remove the cyst surgically, or use carbon dioxide laser to remove it cleanly after the pathology is clearly diagnosed.