(Disclaimer: This article is only for popular science purposes, in order to protect the privacy of patients, the following content of the relevant information has been processed) Abstract: The patient Yang 1 year ago waist long a pimple, no pain, no itch, recently the pimple gradually grow. He came to the dermatology clinic and found a soybean-sized subcutaneous cyst on the left side of his waist. He was diagnosed as an epidermoid cyst, and was recommended to have it surgically removed because it was growing gradually. The pathologic examination after the removal was consistent with the diagnosis of epidermoid cyst, and there was no obvious scarring after the operation, and the cyst did not recur during the follow-up. Basic information] Male, 25 years old [Disease type] Epidermoid cyst [Hospital] Maanshan Seventeen Metallurgical Hospital [Time of consultation] April 2022 [Treatment plan] Surgical excision + local anesthesia (Lidocaine hydrochloride injection) [Treatment cycle] Outpatient treatment, 1 week, 1 month review [Treatment effect] Epidermoid cyst excision, no recurrence I. Initial consultation 25-year-old patient Yang complained of a lump in his lower back one year ago. The patient complained that he had a lump on his waist one year ago, which was painless and itchy. Recently, the lump had grown some, and his family thought that it was a bad skin mole, fearing that it would turn into melanoma, and they had to let him come to the hospital to take a look at it. After examination, it was found that a soybean-sized skin cyst, greenish-gray, with a black head in the center, not a pigmented nevus, was seen by the naked eye on the left side of the patient’s waist, and was initially diagnosed as an epidermoid cyst. Although it is not a pigmented nevus that is prone to malignant transformation, epidermoid cyst is easy to grow up and easy to be inflamed when infected, so the patient was recommended to have it removed surgically, and the patient accepted the surgical removal program. The patient was given a blood test and coagulation function check before the surgery, and the surgery was arranged after there was no contraindication, and this kind of surgery was an outpatient surgery without hospitalization. First, the skin was sterilized and local anesthesia was administered with lidocaine hydrochloride injection, and then the skin was incised with a scalpel along the preoperative demarcation line, and then the cyst was gradually separated, and as much as possible, the cyst was completely separated and removed during the operation. After the cyst is removed, the bleeding is stopped, and then the subcutaneous tissue is sutured first, and then the skin is sutured, so that layer by layer suturing can significantly reduce the formation of scar, and after the suture is completed, the skin is sterilized, and then gauze is applied, and the surgery is completed. After surgery, the cyst tissue was examined pathologically, and the results were consistent with the diagnosis of epidermoid cyst. After surgery, the patient was asked to change the dressing regularly, once a day for the first 2 days, and once every other day to avoid wound infection. 1 week later, the stitches were removed in the hospital, and the wound recovered well, with no redness, swelling, infection, etc. After the stitches were removed, the wound was left with threads. After removing the stitches, there was a linear dark red scar at the wound, which was unavoidable due to surgery, and the patient was informed before the surgery that the linear scar would gradually fade with time. 1 month later, the follow-up examination showed that there was no recurrence of the epidermoid cysts, and the surgical scar had faded, and there was no scar hyperplasia. The patient’s epidermoid cyst was successfully removed after surgical treatment. Ask the patient to come to the hospital 1 week to remove the stitches, pay attention to the wound can not touch water within 1 week after the operation, to avoid wound infection, if the incision appears red, swollen, pain and other symptoms, may be infected, this time to go to the hospital in a timely manner, because the infection of the incision is also prone to the formation of keloid scar hyperplasia. Eat a light diet with plenty of fresh vegetables and fruits, and avoid drinking alcohol. Postoperative surgical scar will gradually fade with time, if the scar is more obvious, you can choose laser treatment. V. Personal Insights Epidermoid cysts are usually skin problems caused by abnormal proliferation of subcutaneous hair follicles or sebaceous glands, and sometimes cysts become infected. Some of them will grow gradually, as in this patient. Surgical excision is recommended for such cysts, and the surgery is usually an outpatient procedure, most of which can be completed within 1 hour. Coagulation and platelets should be checked before surgery, and pathology should be done after surgery to remove the cyst tissue to rule out other skin tumors. Wound infection is prevented after surgery. There will be scarring after surgery, but most of the scarring will fade over time.