Definition of Pancoast Tumor
A Pancoast tumor (also called superior sulcus tumor) is a lung cancer arising in the apex of the lung that invades structures of the apical chest wall at the level of the first rib or above. 1
Essential Anatomic Criteria
The formal definition requires:
- Tumor location: Apex of the lung
- Invasion requirement: Apical chest wall structures at the level of the first rib or above
- Classic symptoms NOT required: Horner syndrome and arm pain are common but not necessary for diagnosis 1
Structures Commonly Invaded
These tumors frequently invade:
- Brachial plexus (particularly C8-T1 nerve roots)
- Subclavian vessels
- Spine (vertebral bodies or lamina)
- First and second ribs
- Stellate ganglion 1
TNM Staging Classification
The extent of invasion determines T stage:
- T3 designation: Involvement of T1 or T2 nerve roots OR first rib
- T4 designation: Involvement of C8 or higher nerve roots, cords of the brachial plexus, subclavian vessels, vertebral bodies, or lamina 1
Anatomic Compartments
Modern classification divides these tumors into anterior, middle, and posterior compartment tumors based on the location of chest wall involvement relative to the insertions of the anterior and middle scalene muscles on the first rib. 1
Clinical Presentation
Most patients present with:
- Shoulder or chest wall pain (most common)
- Radicular pain or neurologic findings in the ulnar hand distribution (from C8-T1 brachial plexus invasion)
- Hand swelling (from subclavian or brachiocephalic vein compression)
- Horner syndrome (from stellate ganglion invasion) 1
Important Diagnostic Caveat
Not all apical lung masses are Pancoast tumors. The diagnosis requires documented invasion of apical chest wall structures. Other lesions including granulomas, fungal infections, and small cell lung cancer can present similarly in the superior sulcus region, making tissue diagnosis mandatory before treatment. 1
Pancoast tumors account for less than 3-5% of all lung cancers, with the majority being non-small cell lung cancer (predominantly adenocarcinoma accounting for approximately two-thirds of cases). 2, 3