If you feel a lump in the tendons of your neck, consult general surgery or thyroid surgery for benign tumors such as lipomas, fibroids, and hemangiomas of the neck. It may also be a thyroid-related disease, including thyroid adenoma, thyroid cyst, or thyroid cancer. There may also be swollen lymph nodes in the neck, including benign and malignant lymph node enlargement: 1. Benign lymph node enlargement is usually caused by upper respiratory tract infections, mouth ulcers or gingivitis, and inflammatory diseases of the thyroid gland, such as subacute thyroiditis and Hashimoto’s thyroiditis. 2. Malignant metastatic lymph node enlargement is mainly caused by tumors of the head and face, cysts, and thyroid cancer. This is mainly due to the swelling of lymph nodes in the neck caused by lymphatic tumors of the head and face, malignant tumors of the thyroid gland or malignant tumors of the gastrointestinal tract that metastasize to the neck through the lymphatic vessels, resulting in the symptom of a lump in the tendons of the neck.