Pancoast tumor

Pancoast tumor, also known as superior sulcus tumor, is typically a non-small cell lung cancer (usually squamous cell carcinoma or adenocarcinoma) that arises in the apex of the lung. The tumor's clinical significance stems from its propensity for local invasion rather than early metastasis. It commonly invades the C8-T1 nerve roots of the brachial plexus, causing severe shoulder and arm pain that radiates in an ulnar distribution, along with weakness and atrophy of intrinsic hand muscles. Invasion of the sympathetic chain at T1 produces ipsilateral Horner's syndrome (ptosis, miosis, anhidrosis). The tumor may also invade ribs, vertebrae, subclavian vessels, and the stellate ganglion. Pancoast syndrome refers to the constellation of symptoms including shoulder/arm pain, Horner's syndrome, and hand muscle weakness. Diagnosis requires high clinical suspicion as chest X-rays may miss apical lesions; CT or MRI of the chest and brachial plexus is preferred. Treatment typically involves multimodal therapy with neoadjuvant chemoradiation followed by surgical resection in appropriate candidates.