Chapter 82: Pancoast Tumors

INTRODUCTION

Superior sulcus tumors, otherwise known as Pancoast tumors, are a unique set of bronchogenic carcinomas. Pancoast tumors account for about 3–5% of all non–small-cell lung cancers (NSCLCs) and have several distinctive features.¹ They involve the thoracic inlet and apex of the chest wall and therefore cause a characteristic set of symptoms, depending on which local structures are involved (Fig. 82-1). The 1^st and 2^nd ribs, 1^st and 2^nd thoracic vertebral bodies, lower nerve roots of the brachial plexus, sympathetic chain with associated stellate ganglion, and subclavian vessels are all susceptible to local invasion by superior sulcus tumors. Patients can present with a wide variety of symptoms, including chest interscapular or arm pain, paresthesias, hand-muscle wasting, and Horner syndrome. This constellation of symptoms is called Pancoast syndrome; however, a more accurate term would be the Pancoast-Tobias syndrome,^2–7 as described by two individuals. Although Henry Pancoast, a radiologist, originally described this constellation of symptoms in 1932, he failed to recognize the pulmonary origin of these tumors. Unaware of Pancoast’s report, Tobias, an Argentine physician, described similar clinical findings and ascribed them to the presence of peripheral lung tumors. It is important to differentiate Pancoast tumor from Pancoast syndrome, as not all superior sulcus tumors cause the symptoms associated with the syndrome and some can be subtle and difficult to diagnose. Pancoast tumors have the same biologic behavior as their histologic counterparts that do not occur in the superior sulcus and, therefore, are diagnosed, staged, and treated the same as other NSCLCs. The symptoms associated with this syndrome are caused by the location of the mass and its anatomic proximity to nearby structures.

DIAGNOSIS

Pancoast syndrome tumors are unique in that most or all of the associated symptoms are caused by the invasion of local structures in the apex of the chest rather than the pulmonary sequelae. As such, the diagnosis can be elusive, and patients are often misdiagnosed with shoulder bursitis, ulnar nerve entrapment, or a simple muscle sprain. The presence of at least one of the aforementioned symptoms in the Pancoast-Tobias syndrome should raise one’s suspicion for a superior sulcus tumor. Patients often present with shoulder or elbow pain because of local invasion of the inferior roots of the brachial plexus, and the pain usually follows the ulnar nerve distribution (Fig. 82-2). They can suffer intrinsic hand atrophy and paresthesias along the medial aspect of the forearms and fourth/fifth digits. In extreme cases, patients can be seen using the non-affected arm to hold up the elbow of the affected side, which acts to take pressure off the brachial plexus and provides symptom relief (Fig. 82-3). Additionally, if the tumor involves the sympathetic chain or stellate ganglion, patients will ...