Horner Syndrome is the Most Likely Finding
In a 78-year-old man with lung cancer localized to the apex of the right lung (Pancoast tumor), Horner syndrome is the most likely clinical finding among the options provided.
Clinical Reasoning
Pancoast Tumor Anatomy and Presentation
A lung cancer at the apex is classified as a superior sulcus tumor (Pancoast tumor), which by definition involves structures of the apical chest wall at the level of the first rib or above 1. The anatomic location determines the presenting signs and symptoms through direct invasion of nearby structures.
Horner syndrome occurs when the tumor invades the stellate ganglion, which is anatomically positioned in the apex of the lung 1. This classic triad consists of:
- Ptosis (drooping eyelid)
- Miosis (constricted pupil)
- Anhidrosis (decreased sweating on the affected side)
Why Other Options Are Less Likely
The other answer choices do not represent typical complications of apical lung tumors:
- Middle lobe bronchiectasis (A): This is unrelated to apical tumors and would involve the middle lobe, not the apex
- Pneumothorax (B): Not a characteristic presentation of Pancoast tumors; these are solid masses invading chest wall structures rather than causing air leaks
- Lung abscess (D): This represents an infectious process, not a typical complication of apical malignancy
- Pulmonary hypertension (E): Not associated with localized apical tumors
Additional Expected Findings
Beyond Horner syndrome, patients with Pancoast tumors typically present with 1:
- Shoulder or chest wall pain (most common presenting symptom)
- Radicular pain or neurologic findings in the ulnar hand if the lower brachial plexus (C8-T1) is invaded
- Hand swelling if there is subclavian or brachiocephalic vein compression
Important Clinical Caveat
The guidelines explicitly note that Horner syndrome is not required for the diagnosis of a Pancoast tumor—invasion of apical chest wall structures at the first rib level or above is sufficient 1. However, when Horner syndrome is present, it is highly characteristic of this tumor location and represents invasion of the stellate ganglion.
Answer: C) Horner syndrome