A 55-year-old male bodybuilder presents to the emergency department with weakness of his right arm. The patient states he has experienced these symptoms for a few weeks; however, today his hand felt so weak he dropped his cup of tea. The patient has a medical history of diabetes. He drinks 2-7 alcoholic drinks per day and has smoked 2 packs of cigarettes per day since he was 25. The patient uses anabolic steroids. He has lost 17 pounds since he last came to the emergency department 1 month ago. His temperature is 99.5°F (37.5°C), blood pressure is 177/108 mmHg, pulse is 90/min, respirations are 17/min, and oxygen saturation is 98% on room air. Physical exam reveals decreased sensation in the right arm and 2/5 strength in the right arm and 5/5 strength in in the left arm. The patient states that he is experiencing a dull aching and burning pain in his right arm during the exam. Symptoms are not changed with changes in head and neck position. Which of the following is the most likely diagnosis?
Apical lung tumor
Brachial plexopathy
Cerebral infarction
Scalenus anticus syndrome
Apical lung tumor
This patient is presenting with unilateral upper extremity paresthesia and weakness suggestive of compression of the neurovascular structures of the upper extremity secondary to an apical lung tumor.

An apical lung tumor can compress the neurovascular structures in its proximity and cause pain, numbness, and weakness of the ipsilateral arm. A Horner syndrome can also be observed with compression of the sympathetic chain leading to ipsilateral miosis, ptosis, and anhidrosis in some cases. These malignancies typically occur in older male smokers and can be associated with symptoms such as fatigue, cough, and weight loss. Chest radiography will demonstrate an apical opacity and CT scan can confirm the size and location of the mass. Treatment is with chemotherapy and surgical excision of the tumor.

Davis and Knight review the evidence regarding the diagnosis and treatment of patients with apical lung tumors. They discuss how these tumors can be associated with brachial plexus injuries. They recommend surgical excision of these tumors if they are resectable.

Incorrect Answers:
Answer B: Brachial plexopathy could present with weakness and numbness of the ipsilateral arm but is a less likely diagnosis (and a diagnosis of exclusion). Treatment is with identification and surgical release of any underlying anatomic defects (such as compressive bands) and supportive therapy if none are found.

Answer C: Cerebral infarction (stroke) would present with sudden onset of acute neurological deficits. These would typically only affect one side of the body and would not necessarily be associated with a dull pain or numbness that is chronic. Treatment is with thrombolytics if patients meet criteria for acute therapy.

Answer D: Scalenus anticus syndrome occurs in bodybuilders or athletes with hypertrophied neck muscles that compress the brachial plexus. Symptoms are typically worsened by certain positions. Treatment is with physical therapy and surgical decompression in refractory cases.

Answer E: Subclavian steal syndrome presents with numbness, tingling, weakness in a limb, and CNS symptoms (vertigo, slurred speech, or stroke-like symptoms) that are worsened with activity and relieved with rest. Treatment is with vascular intervention to restore blood flow.

Bullet Summary:
Apical lung tumors can compress neurovascular structures in the upper extremity and cause pain, numbness, and tingling in the ipsilateral arm.