Bottom line: Most cases of Pancoast syndrome are caused by NSCLC. However, there have been case reports of other causes, including other primary thoracic tumors, metastases, lymphoma, infectious diseases, neurogenic thoracic outlet syndromes, and pulmonary amyloid nodules. Only about 5% of NSCLC involves Pancoast syndrome.
Summary: Arcasoy SM, Jett JR. Superior pulmonary sulcus tumors and Pancoast’s syndrome. N Engl J Med. 1997; 337(19): 1370 -1376
Pancoast syndrome was first identified as a tumor at the apex of the lung inducing the triad of shoulder and/or arm pain, Horner syndrome, and paresthesias in the ulnar nerve distribution of the hand. Other etiologies described in the literature are summarized in Table 1.