A hard bump on top of the shoulder that has no obvious symptoms and requires no special treatment may be a localized cyst. The hardness is relatively large, the tension is relatively high, and it is hard to touch. It may also be a huge lipoma or sebaceous cyst, or it may be caused by a localized muscle herniation. You can first go to the hospital to improve the ultrasound examination and MRI examination for preliminary determination. If there is no discomfort, continue to observe, but avoid local compression, repeated rubbing and massage to prevent adverse reactions and changes. Surgical excision can also be performed, and pathological examination after surgical excision is the gold standard for differential diagnosis. If you continue to observe and the local bumps increase in size, pain, hardening, redness, swelling or other itchy abnormal changes occur later, you need to go to the hospital for diagnosis and treatment in a timely manner, as malignant changes may occur.