A small nipple growing next to the armpit is considered to be a parametrium, which is usually found in the armpit and is a congenital developmental abnormality that occurs bilaterally in many patients and can be further defined by ultrasonography. The parametrial glands are benign, but if they gradually increase in size, they will not only affect the aesthetics, but some patients may even experience hyperplasia of the parametrial glands, which can be characterized by regular pain and swelling. If necessary, surgical treatment can be chosen. Depending on the size of the lesion and the site of occurrence, local anesthesia or intravenous anesthesia can be chosen, and intravenous anesthesia is relatively more expensive. Although the parametrium is a benign disease, if the history of the disease is long, there is a possibility of malignant transformation and even metastasis to distant organs and axillary lymph nodes.