In 1932, Pancoast defined a
superior pulmonary sulcus tumor as a mass growing at the thoracic
inlet that produces a constant and characteristic clinical
presentation of pain in an eighth cervical or first and second
thoracic trunk distribution.
Pancoast tumors are a subset of lung cancers
that invades the apical chest wall. Because of their location in the
pleural apex, they invade adjoining tissue. Although various other
tumors may produce a similar clinical presentation because of their
location at the thoracic inlet, the most common cause is generally
believed to be a bronchogenic carcinoma arising in or near the
superior sulcus and invading the adjacent extrathoracic structures
by direct extension. The location of the tumor, rather than its
pathology or histology of origin, is significant in producing its
characteristic clinical pattern.
Carcinomas in the superior pulmonary sulcus
produce Pancoast syndrome, thus causing pain in the shoulder and
along the ulnar nerve distribution of the arm and hand. (These
carcinomas also cause Horner syndrome.) These apical lung tumors
tend to be locally invasive early. In the absence of metastases and
regional nodal involvement, these apical cancers can be successfully
Careful assessment and appropriate staging is performed prior to
surgery, and selected patients are administered preoperative
irradiation of 30 Gy over 2 weeks. After a 2- to 4-week interval,
surgical resection of the chest wall and lower brachial plexus and
en bloc lung resection produces a 5-year survival rate of 30%.
Contraindications to surgery include an extension of the tumor into
the neck or vertebrae, the presence of substantial mediastinal lymph
nodes, and peripheral tumor dissemination. Newer protocols that use
combinations of irradiation, chemotherapy, and surgery are currently
being studied to determine the best therapy
Pancoast tumors are much less common than other lung cancers. In
past series, the rate of Pancoast tumors varied from 1-3% of all
lung cancers. A major issue with Pancoast tumors is the delay in
diagnosis. The apical lung cancer may not be visualized on an
initial chest radiograph, and, by the time the patient presents with
symptoms, the tumor has almost always invaded nearby structures. In
addition, the symptoms produced by the disorder can be mimicked by
numerous neurological or musculoskeletal disorders, thus delaying
The risk factors for almost all lung cancers are similar. These
include prior prolonged asbestos exposure, exposure to industrial
elements (eg, gold, nickel), smoking, and secondary smoke exposure.
The mass in the superior sulcus is an extension of a lung tumor;
most of it lies outside the lung and involves the chest wall, nerve
roots, lower trunks of the brachial plexus, sympathetic chain,
stellate ganglion, ribs, and bone. Most Pancoast tumors are squamous
cell carcinomas or adenocarcinomas. Only 3-5% are small cell
carcinomas. Squamous cell carcinoma occurs more frequently, although
large cell and undifferentiated types are also common.
Adenocarcinoma is sometimes found in this location and can even be
metastatic. Involvement of the phrenic or recurrent laryngeal nerve
or superior vena cava obstruction is not representative of the
classic Pancoast tumor.
The symptoms are typical of the location of the tumor in the
superior sulcus or thoracic inlet adjacent to the eighth cervical
nerve roots, the first and second thoracic trunk distribution, the
sympathetic chain, and the stellate ganglion. Initially, localized
pain occurs in the shoulder and vertebral border of the scapula.
Pain may later extend along an ulnar nerve distribution of the arm
to the elbow and, ultimately, to the ulnar surface of the forearm
and to the small and ring fingers of the hand (C8). If the tumor
extends to the sympathetic chain and stellate ganglion, Horner
syndrome and anhidrosis develop on the ipsilateral side of the face
and upper extremity. Pain is frequently relentless and unremitting,
often requiring narcotics for relief. The patient usually supports
the elbow of the affected arm in the hand of the opposite upper
extremity to ease the tension on the shoulder and upper arm.
The hand muscles may become weak and atrophic,
and the triceps reflex may be absent. The first or second rib or
vertebrae may be involved by tumor extension and intensify the
severity of pain. The spinal canal and spinal cord may be invaded or
compressed, with subsequent symptoms of spinal cord tumor or
cervical disk disease. Confusion with thoracic outlet syndrome and
cervical disk disease is common in the early clinical course.
Careful neurologic examination, electromyographic studies, and ulnar
nerve studies are performed to verify the precise diagnosis.
Infrequently, a patient with a Pancoast tumor
may also have features of a paraneoplastic syndrome. Most of the
metabolic manifestations are the result of the secretion of
endocrine chemicals by the tumor. Manifestations encompass Cushing
syndrome, excessive antidiuretic hormone secretion, hypercalcemia,
myopathies, hematological problems, and hypertrophic
osteoarthropathy. The presence of paraneoplastic syndromes does not
connote unresectability, but most of these are associated with small
Compared with other examinations, MRI is more accurate in
identification of the extent of tumor involvement; it is superior to
CT scanning in the detection of invasion of adjacent organs (eg,
vertebral bodies, brachial plexus, subclavian vessels).
Differential diagnoses of masses in the apical chest include
primary tumors of the thyroid, larynx, and pleura. Other causes may
include infectious disorders of the lung, aneurysms of the
subclavian vessels, amyloid of pleura, and multiple myeloma. The
differential diagnoses of arm and shoulder pain are extensive;
however, primarily, thoracic outlet syndrome and cervical disk
disease must be excluded.
In the very rare patient, sputum cytology has been helpful.
Initially, most Pancoast tumors are diagnosed histologically based
on transthoracic needle biopsy results. Diagnosis via bronchoscopy
is less helpful because most of these tumors are peripherally
located. The flexible scope is more useful than the rigid scope in
obtaining bronchoscopic aspirates and brush biopsy specimens.
Liver, bone, and brain scans are performed to
determine the presence of any metastatic disease. Although more than
90% of patients can be correctly diagnosed based on clinical and
radiological findings alone, open biopsy of the tumor for
pathological validation may be performed through a supraclavicular
incision. Results from a needle biopsy through the supraclavicular
or posterior triangle are also successful in confirming the
diagnosis and in delineating the cell type prior to treatment. Even
though clinical diagnosis is relatively simple, performing a tissue
biopsy is still necessary.
Staging is determined by the location of the lesion and its
metastases. The true Pancoast tumor is usually T3, which describes
the extension of the tumor through the visceral pleura into the
parietal pleura and the chest wall. Pancoast tumors are classified
as T4 when mediastinal invasion, cervical invasion, or both have
occurred. Peripheral metastases signal a poor prognosis, and surgery
is contraindicated in such cases.
Mediastinoscopy is used for staging to
delineate the metastases to mediastinal lymph nodes. Cervical
mediastinoscopy is indicated for right pulmonary lesions; a
Chamberlain procedure (left second interspace mediastinoscopy) is
indicated for left pulmonary lesions. Generally, mediastinoscopy is
performed if the lymph nodes appear larger than 1 cm in diameter on
a CT scan because the accuracy of CT scan results for predicting
metastatic involvement in enlarged lymph nodes is only 70%.
Conversely, if the CT scan does not reveal any enlarged lymph nodes,
the patient is deemed operable. If the nodes in the mediastinum are
positive, the prognosis is poor. The exception to this rule is an
upper lobe lesion with positive nodes on the right side of the
trachea only. If these are internodal, spread is considered local,
and the tumor may still be resectable.
Contraindications: Contraindications to
surgery include (1) extensive invasion of the neck, brachial plexus,
or vertebrae; (2) perinodal mediastinal extension; and (3)
peripheral metastases. These include extrathoracic metastatic
disease and positive mediastinal nodes. Complete upper and lower
brachial plexus invasion is a relative contraindication, provided
complete surgical excision can be performed. Vertebral body
involvement should not be a contraindication unless invasion of the
cortex is confirmed.
Patients with poor respiratory function and
ischemic coronary artery disease need a proper workup prior to
surgery. Heart failure, recent myocardial infarction, and unstable
angina are contraindications for surgery. Although many patients are
elderly (the age group with the highest risk of complications), age
alone is relatively unimportant if the patient is in otherwise good
Contraindications to surgery can be summarized
Subclavian venous obstruction
- Extensive involvement of brachial plexus
- Involvement of paraspinal region
- Involvement of lamina of vertebrae body
- Involvement of mediastinal lymph node