There are more possible causes for a small meatball growing in this armpit, mainly including the following aspects: 1. Local lymph nodes are a relatively common situation, and lymph nodes occur mainly due to reactive hyperplasia, or possibly lymph node metastasis caused by breast cancer. Patients need to go to the hospital for ultrasound examination to clarify the diagnosis and further treatment if necessary. 2. local benign subcutaneous occupations, including lipomas, hemangiomas, fibroids, etc., patients need to go to the hospital for ultrasound examination to determine, if larger, surgical treatment is required. 3. occurring in women due to the impact of localized parametrium, which is congenital, patients generally have their own understanding is not easy to misdiagnose. 4. The local skin redundancy, mainly related to the local skin by friction, disposal is relatively simple laser treatment can be.