A ball of flesh under the armpit can be caused by skin tags, cysts, enlarged lymph nodes, benign tumors, and so on. 1. skin tattoos: abnormal skin growths, also known as warts, is a benign disease, in the dermatology laser freezing operation can be removed. 2. cysts: armpit long a ball of meat may be the hair follicles are not fluent, resulting in the accumulation of secretions formed sebaceous cysts. 3. lymph node swelling: inflammation caused by localized armpit lymph node swelling, lymph node swelling, benign tumors. 3. swollen lymph nodes: local axillary lymph node swelling caused by inflammation, such as acute mastitis, lymphatic tuberculosis; malignant tumor metastasis resulting in axillary lymph node swelling, such as breast cancer, can also lead to a meatball under the armpit. 4. Benign tumors: finally, a meatball under the armpit may also be a benign tumor, such as subcutaneous lipoma. In conclusion, if you find a meatball under the armpit, you should go to the hospital in time, and it is recommended to have a systematic examination under the guidance of doctors in regular specialized hospitals in order to make a clear diagnosis and avoid any adverse effects.