Possible reasons for shoulder pain caused by thyroid cancer include: thyroid enlargement compresses cervical plexus nerve, lymph node metastasis compresses brachial plexus nerve, and bone metastasis occurs in late stage.
1. Compression of cervical plexus nerve: thyroid cancer can compress cervical plexus nerve when the thyroid gland is enlarged to a certain degree, thus causing pain in occipital area, neck and shoulder.
2. Thyroid cancer is prone to cervical lymph node metastasis, followed by enlarged lymph nodes. When the lymph nodes are enlarged to a certain extent, it can cause compression of brachial plexus nerves, resulting in pain, numbness, abnormal sensation and weakness of shoulder and upper limbs.
3. Bone metastasis can occur in the late stage of thyroid cancer, which can cause persistent severe pain when metastasized to scapula and humerus, and can lead to pathological fracture in serious cases.
When thyroid cancer is found, it is recommended that patients go to the hospital as soon as possible to improve relevant examinations such as cervical and thoracic CT, PET-CT, lymph node ultrasound, etc., so as to clarify the pathological type and stage in time, and then treat it under the guidance of professional doctors.