Differential Diagnosis for Pain in Left Neck, Arm, and Collarbone with Swelling and Hypertension

Single Most Likely Diagnosis

• Thoracic Outlet Syndrome (TOS): This condition involves compression of the nerves and/or blood vessels that pass into the thoracic outlet (the space between your collarbone and first rib). It can cause pain in the neck, arm, and collarbone, along with swelling due to impaired venous return. Hypertension might be secondary to pain or could be a coincidental finding.

Other Likely Diagnoses

• Cervical Spondylosis or Herniated Disk: These conditions can cause neck and arm pain due to nerve root compression. Swelling might be less common but could occur due to muscle spasm or local inflammation. Hypertension could be related to chronic pain.
• Costoclavicular Syndrome: Similar to TOS, this involves compression of the neurovascular bundle between the clavicle and the first rib, leading to similar symptoms.
• Pancoast Tumor: A type of lung cancer located at the top of the lung, which can cause shoulder and arm pain, along with swelling if it invades nearby structures. Hypertension might be seen due to various paraneoplastic syndromes.

Do Not Miss Diagnoses

• Aortic Dissection: Although less likely, this is a medical emergency. Pain in the neck and arm could be referred from the aortic arch, and hypertension is a common finding. Swelling could occur if there's impairment of blood flow to the arm.
• Subclavian Artery Aneurysm or Thrombosis: These conditions can cause arm swelling and pain due to impaired blood flow. Hypertension might be a contributing factor or a result of the condition.
• Cervical Rib or Other Bony Abnormalities: Can cause TOS or similar syndromes, leading to the described symptoms.

Rare Diagnoses

• Neurogenic Tumors: Such as neurofibromas or schwannomas, which can cause nerve compression leading to pain and swelling.
• Paget's Disease of Bone: A condition of bone that initially results in the overproduction of bone material, which can lead to enlarged and deformed bones. This could potentially compress nerves or blood vessels, leading to the described symptoms.
• Ehlers-Danlos Syndrome: A group of disorders that affect connective tissues supporting the skin, bones, blood vessels, and many other organs and tissues. It could potentially lead to vascular or musculoskeletal issues causing the symptoms described.