A small ball in the armpit that looks like a bead when pressed may be an enlarged lymph node or lipoma. 1. Enlarged lymph node: enlarged lymph node, through clinical examination, is mainly ovoid, with large mobility and clear demarcation with surrounding tissues, which can be directly diagnosed through ultrasound examination. 2. Lipoma: Lipoma itself is not clearly demarcated from the surrounding adipose tissue, with small mobility and homogeneous fat echoes by ultrasound. For further investigation, it is necessary to go to the surgery firstly to judge by ultrasound examination, and then make further treatment after judging the specific condition clearly. If there is no symptom in itself, you can observe first to avoid repeated stimulation, some lymph nodes will appear reactive enlargement; if there are pain symptoms, you need to go to the hospital to improve the examination, after a clear diagnosis, under the guidance of the clinician to do standardized treatment.