Pancoast tumor, otherwise known as superior sulcus tumor, refers to a relatively uncommon situation where a primary bronchogenic carcinoma arises in the lung apex at the superior pulmonary sulcus and invades the surrounding soft tissues.
Definitions vary from author to author, with some only referring to Pancoast tumors if the histology is of non-small cell lung cancer (NSCLC), and treating other superior sulcal tumors separately (even though the latter can also cause Pancoast syndrome) 7; and some only referring to Pancoast tumors if they have presented with Pancoast syndrome and call the rest superior sulcus tumors.
Others use the term superior sulcal tumor and Pancoast tumor interchangeably, but limit the use to bronchogenic carcinomas, while others include all tumors that involve the superior pulmonary sulcus (whether or not they arise from the lung).
For the sake of simplicity, we have taken the middle road. For this article superior sulcus tumor and Pancoast tumor are used interchangeably to refer to a primary bronchogenic carcinoma involving the superior pulmonary sulcus.
Superior sulcus tumors account for 3-5% of all bronchogenic carcinomas and have similar demographics to other lung cancers (see bronchogenic carcinoma article for a discussion of demographics and risk factors) 5,8.
The most common symptoms at presentation are chest and/or shoulder pain, with arm pain being also common. Weight loss is frequently present 5.
Superior sulcus tumors are usually non-small cell lung cancers (NSCLC). The most common histology encountered historically in the superior sulcus were squamous cell carcinomas 6,7, however, more recently, and in keeping with the overall shift in frequency, bronchogenic adenocarcinomas now are more frequently identified 8.
Plain films demonstrate a soft tissue opacity at the apex of the lung. Occasionally rib involvement or extension into the supraclavicular fossa may be evident. Lordotic views may be helpful.
The role of ultrasound is limited, but it may be useful in aiding percutaneous biopsy as it can visualize the external component of the tumor via an intercostal or supraclavicular acoustic window 3.
Although, as is the case with bronchogenic cancer at other locations, CT is the workhorse for diagnosis, it has poor sensitivity (60%) and specificity (65%) for accurate local staging 7. It is, however, excellent at identifying bony involvement.
MRI is helpful in the assessment of superior sulcus tumors due to its excellent demonstration of soft-tissue involvement and is far more sensitive (88%) and specific (100%) for local staging 7.
Careful assessment of the brachial plexus is important as the involvement of more than the lower trunk, or C8 nerve root, is usually considered inoperable 7.
The anatomy lends itself particularly to imaging in the coronal and sagittal plane, and the T1 sagittal images offer most of the required information 2,8.
As for bronchogenic carcinomas in general, it is useful for assessing nodal and distant metastases at the baseline staging. For Pancoast in particular, PET-CT permits an accurate delineation of the gross tumor volume, which will be essential for the radiation treatment planning 8.
Treatment and prognosis
Treatment depends crucially on the extent of involvement notably through the apex, as these lesions usually involve the brachial plexus and subclavian vessels. In such lesions, radiotherapy is typically administered in an attempt to downstage the tumor sufficiently to allow for attempted resection 2.
Much controversy nonetheless exists over exact inclusion and exclusion criteria for surgery and the timing and administration of radiotherapy and chemotherapy.
Despite advances in management, prognosis remains poor with an overall 5-year survival of only 36%. Complete resection is the most important factor in determining survival 5:
- complete resection achieved - 45% 5-year survival
- incomplete resection only - 0% 5-year survival
History and etymology
Pancoast syndrome as a result of superior sulcus tumors was described in some publications (Hare 1838 and Ciuffini in 1911) before Pancoast reported it using the term 'superior pulmonary sulcus tumor' in 1924 5,8,9:
- Edward Selleck Hare (1812-1838), British physician, who died tragically at the age of 26 years from typhus 10
- Publio Ciuffini , Italian physician ref
- Henry Khunrath Pancoast (1875-1939) 11, American radiologist
General imaging differential considerations include:
- pulmonary metastases
- primary chest wall tumors
- chest wall metastases
- apical pleural thickening secondary to e.g. previous pulmonary tuberculosis
In addition a number of plain film mimics should be considered, including:
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- 2. Heelan RT, Demas BE, Caravelli JF et-al. Superior sulcus tumors: CT and MR imaging. Radiology. 1989;170 (3): 637-41. Radiology (abstract) - Pubmed citation
- 3. Yang PC, Lee LN, Luh KT et-al. Ultrasonography of Pancoast tumor. Chest. 1988;94 (1): 124-8. doi:10.1378/chest.94.1.124 - Pubmed citation
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- 5. Alifano M, D'aiuto M, Magdeleinat P et-al. Surgical treatment of superior sulcus tumors: results and prognostic factors. Chest. 2003;124 (3): 996-1003. doi:10.1378/chest.124.3.996 - Pubmed citation
- 6. Collins J, Stern EJ. Chest radiology, the essentials. Lippincott Williams & Wilkins. (2007) ISBN:0781763142. Read it at Google Books - Find it at Amazon
- 7. Pass HI. Lung cancer, principles and practice. Lippincott Williams & Wilkins. (2005) ISBN:0781746205. Read it at Google Books - Find it at Amazon
- 8. Bruzzi JF, Komaki R, Walsh GL et-al. Imaging of non-small cell lung cancer of the superior sulcus: part 1: anatomy, clinical manifestations, and management. Radiographics. 28 (2): 551-60. doi:10.1148/rg.282075709 - Pubmed citation
- 9. Pancoast HK. Importance of careful roentgen-ray investigation of apical chest tumors. (1924) Journal of the American Medical Association. 83 (18): 1407. doi:10.1001/jama.1924.02660180025007
- 10. Fulton JF. Edward Selleck Hare (1812-1838) and the Syndrome of Paralysis of the Cervical Sympathetic. (1929) Proceedings of the Royal Society of Medicine. 23 (2): 152-7. Pubmed
- 11. Pendergrass EP. Henry Khunrath Pancoast, M.D. (1875–1939). Radiology. 1939; 33 (4): 526-527. doi:10.1148/33.4.526