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Pancoast's syndrome results from bronchogenic carcinoma in the superior pulmonary sulcus. The classic syndrome includes pain in the shoulder, arm, and hand in the distribution of C8 and T1 nerve roots, weakness and atrophy of the hand muscles, Horner's syndrome, and first rib erosion secondary to Pancoast's tumor in the superior thoracic inlet. Anatomically, the superior pulmonary sulcus is the area on the superior surface of the lung traversed by the subclavian vessels and encircled by the first rib and spine (Fig. 67-1). It also may be described as the thoracic outlet or thoracic inlet. The treatment of choice has been preoperative irradiation (3000 rads over 2–3 weeks) followed by surgical en bloc resection of the lung, chest wall, lower brachial plexus, and vertebrae at a 1-month interval. This effects approximately a 35% 5-year survival with N0 stage I patients. In recent years, chemoinduction therapy in combination with this protocol has markedly improved survival.
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BACKGROUND Edward Hare in 1838 described a patient with pain and numbness in the area of his left ulnar nerve with Horner's syndrome associated with a tumor in the left side of his neck. Henry K. Pancoast, a radiologist, in 1924 described the clinical radiographic findings of four patients with pain in the upper extremity, Horner's syndrome, and erosion of the first rib and vertebra secondary to cancer in the superior pulmonary sulcus. He presented seven patients in 1932, from which resulted the eponym Pancoast's tumor and Pancoast's syndrome. He localized the lesions to tumors in the thoracic outlet or inlet. He coined the term superior pulmonary sulcus tumorrather than apical chest tumor but mistakenly felt that these tumors came from the embryonic cell rest of the fifth branchial cleft. Tobias recognized that these tumors produced a "painful apical costovertebral syndrome" and were secondary to cancers of pulmonary origin. Pancoast's syndrome may be produced by both benign and malignant lesions but most frequently is secondary to carcinomas of bronchogenic origin. In the early 1950s, these tumors were considered unresectable and were treated primarily by irradiation therapy only. Few patients survived. Midway through the irradiation therapy of one patient in 1951, the patient became extremely ill, and irradiation was stopped. Dr. Robert Shaw (my senior partner) elected to resect the lesion because the patient's pain was still severe. This was done empirically approximately 4 weeks after the 3000 rads had been delivered over a 2–3 week period. The patient subsequently became pain-free and lived 15 years thereafter without evidence of disease, expiring from another cause. This successful outcome caused our group to treat several other patients in similar fashion with 3 000 rads to the tumor and mediastinal lymph nodes over a period of 2–3 weeks, followed by a waiting period of 2–4 weeks. This delay allows time for the benefits of irradiation, which theoretically include shrinking of the tumor, blocking of the lymphatics, and weakening of the cells that might be left after surgery because the margins are extremely close in such tumor resections. In 1961, 14 patients were reported, with approximately 40% 5-year survival shown.1 Chardack and MacCallum presented a patient in 1953 and 1956 who had been resected and treated successfully with postoperative irradiation therapy.2,3 This approach, however, has not been as reproducible in other centers as a successful technique. |
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DIAGNOSIS Clinical Presentation Most patients present with shoulder and elbow pain because of involvement of the lower trunk of the brachial plexus. The discomfort often follows the distribution of the ulnar nerve because of malignant invasion of T1 and C8 nerve roots and extension into the parietal pleura and first rib.4 Weakness and atrophy of the intrinsic muscles in the hand, along with pain and paresthesias in the medial aspect of the arm and fourth and fifth digits (distribution of the ulnar nerve), sometimes associated with a loss of the triceps reflex, also are caused by C8 and T1 nerve root involvement. Pain may radiate into the neck and head and posteriorly into the scapular area or anteriorly into the chest (Fig. 67-2).
Classically, the patient presents holding the elbow with the opposite arm to support the shoulder and take the pressure off the brachial plexus for symptomatic relief4,5 (Fig. 67-3). Frequently, the diagnosis is missed because of concentration on cervical osteoarthritis, discs, or other differential diagnoses, often delaying recognition of the true etiology. Horner's syndrome classically presents as an ipsilateral ptosis, with narrowing of the palpebral fissure, myosis, and anhidrosis. It is produced by involvement of the sympathetic chain in the area of C7 and C8, the upper two-thirds of the stellate ganglion6 (Fig. 67-4). Vertebral involvement and spinal cord compression with paralysis (paraplegia) are observed occasionally. Phrenic or recurrent laryngeal nerve invasion is present infrequently, producing diaphragmatic paralysis or hoarseness. Superior vena cava syndrome may result if anterior tumors are present. This syndrome leads to swelling of the face and distention of the neck and upper chest wall veins. Primary pulmonary tumors also may produce the usual symptoms of cough, hemoptysis, dyspnea, wheeze, and weight loss.
Radiographic Observations Chest roentgenographs (posteroanterior and lateral) are the simplest methods of discerning an apical mass (Fig. 67-5A ). Apical lordotic chest views are valuable after the screening procedure. CT scan of the chest provides additional information, particularly about bone invasion (including the first rib) and vertebral involvement (Fig. 67-5B ). It also may be used to delineate lung and liver metastases. MRI is particularly helpful in soft tissue areas, such as invasion of the brachial plexus and chest wall, as well as lymph node metastases in the mediastinum7 (Fig. 67-5C ).
Diagnostic Tests The definitive diagnosis is established by a transthoracic needle biopsy, usually through the supraclavicular space or the posterosuperior chest between the scapula and spine. These small needles are guided by fluoroscopy, ultrasound, or CT in most cases. The first description of transcervical biopsy via the supraclavicular approach was reported by McGoon in 1964.8 Biopsy may be performed under local or general anesthesia. The diagnostic yield for needle biopsy is greater than 90%. Video-assisted thoracoscopy may be used for diagnosis, but patients also may be treated without a diagnosis if the symptoms are classic and the needle biopsy is negative.4 Diagnostic yield from sputum cytology is less than 20%, and for bronchoscopy (fiberoptic or rigid), it is less than 30%.9 The diagnostic yield is low because most of these tumors are peripheral. Staging and Perioperative Assessment Cervical mediastinal lymph node exploration is necessary before treatment in these patients to establish whether the lymph nodes are positive. The suggestion of enlarged nodes on either the CT scan or MRI may be helpful, but the staging of actual metastases is critical.10 False-positive results are present in both directions. If the mediastinal nodes are positive for a right upper lobe lesion, it is still treated as an operable case because the lymph nodes are assumed to be "regional." Contrarily, for a left upper lobe metastasis to the mediastinal lymph node, surgical therapy is less likely to be successful. Perinodal lymph node metastasis portends a worse prognosis than intranodal metastasis.4 Invasion of the vertebral body (T4) demonstrated by CT usually renders a patient inoperable because "no reported cures" have resulted with vertebral involvement in our experience.7 Distant metastases are suspected by history and physical examination, as well as by blood tests including liver chemistries and CT scan and MRI of the mediastinum, retroperitoneum, liver, and adrenal glands. Cell types encountered are predominantly squamous cell carcinoma, with large cell the second and adenocarcinoma the third most commonly observed.11 Many begin as "scar" carcinomas or are secondary to other malignancies.12–16 Metastatic carcinoma from other organs may produce similar symptoms in this area. Various other etiologies include benign tumors and infections such as actinomycosis, tuberculosis, Allescheria infection, cryptococcosis, and hydatid cyst.17–24 Vascular aneurysms25 and amyloidosis26 also may produce the syndrome. Differential Diagnosis Differential diagnosis includes thoracic outlet syndrome (TOS; see Chaps. 123 and 124), which may mimic the symptoms of ulnar paresthesias and pain. First rib resection has been carried out mistakenly for TOS in patients with superior sulcus tumor of the lung.4 Esophageal and cardiac disease also can mimic symptoms of superior pulmonary sulcus tumors, and these areas should be ruled out in the differential diagnosis.4 Indications for Surgery If the patient has a tumor in the area of the superior pulmonary sulcus with or without rib involvement and with or without lower brachial plexus involvement, and it is staged as a T3N0 or N1, he or she is operable. N2disease is operable if it is in the right upper lobe and the mediastinal nodes are considered to be intranodal metastases. Involvement of the vena cava and subclavian artery or vein is not a contraindication for surgery. Although vertebral involvement traditionally has been a contraindication for surgical resection of superior sulcus carcinoma, recent advances in spinal instrumentation have permitted a more complete resection of vertebral body tumor. Gandhi and colleagues have published good results in 17 patients with vertebral resection of carcinoma extension.27 Contraindications include extensive involvement of the brachial plexus, mediastinal perinodal involvement, significant invasion of the soft tissues of the neck, and distant metastasis. Palliative resection is performed occasionally for intractable pain.7 |
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TREATMENT Preoperative Radiotherapy Followed by Surgery After preoperative radiotherapy (3000 rads delivered over 2–3 weeks) followed by a 4-week waiting period, surgical extirpation with an en bloc resection of the pulmonary tumor, chest wall, lower brachial plexus, and vertebrae through the posterior thoracoplasty approach is performed. The en bloc resection of the pulmonary tumor and chest wall is accompanied by resection of the sympathetic chain, the lower trunk of the brachial plexus in most cases (T1 nerve root in most cases; C8 nerve root less frequently), and rarely, the subclavian artery with an interposed graft. A margin of vertebral body is removed with all tumors. A segmentectomy, subsegmental resection, lobectomy, or pneumonectomy is performed to complete the en bloc dissection. Chest wall replacement is required occasionally for anterior tumors but usually not for those lying under the scapula. If six or more ribs are taken, posterior reconstruction with Marlex or other synthetic material is important to keep the scapula from sticking inside the chest.28 The anterior cervical approach championed by Dartevelle and colleagues29 involves a median sternotomy and cervical resection of the clavicle, as well as en bloc resection of the artery, often the vein, and the tumor. This operation is described in Chapter 68 of this textbook. The long-term results with this approach, however, have not been gratifying. Chemotherapy Induction chemotherapy combined with radiation has markedly improved the treatment of superior sulcus tumors. Wright and colleagues from Massachusetts General Hospital reported significant improvement in complete resection rate, pathologic response, 2- and 4-year survival, and reduction of local recurrence with CT/radiation induction therapy over induction radiation therapy alone in over 30 patients.30 Since then, they have treated 15 more patients (total 30), and there have been 2 distant recurrences. The 5-year survival approaches 50%. The Southwest Oncology Group reported less good results with combination chemo/radiation induction therapy, but this was a multicenter study in contrast to the preceding study.31 |
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SURGICAL TECHNIQUE After induction of general anesthesia, the patient is intubated with a double-lumen endotracheal tube. The patient is placed in the lateral decubitus position with an axillary roll under the "down" side (Fig. 67-6). The incision begins above the angle of the scapula, halfway between it and the spinous processes (i.e., thoracoplasty technique), and extends inferiorly, angling anteriorly around the tip of the scapula. The subcutaneous tissue is divided, followed by trapezius and rhomboid muscles and then the posterior superior serratus muscle.
The intercostal muscle overlying the fourth rib is incised. A Finochietto retractor is placed between the top of the fourth rib and the scapula. Since double-lumen intubation is used for the operation, the lung is already collapsed. The fourth interspace is opened. The surgeon places a hand in the patient's chest to palpate the tumor and determine its extent, the number of ribs involved, and the length of each rib to be resected (Fig. 67-7). If the tumor is large, a lower interspace may be used.
Anteriorly, the ribs are divided with the rib shears after ligating, dividing, or clipping the neurovascular bundle under each rib. The dissection is carried up to and through the first rib. Posteriorly, the ribs are sheared off with an osteotome, taking the rib at the level of the transverse processes or a small segment of vertebrae, if necessary. The intercostal bundles may be cauterized or clipped. This is carried through the third, second, and first ribs. Patients with CT evidence of tumor invading the vertebrae are considered inoperable. However, if at operation the tumor is found to lie adjacent to the vertebrae, a margin of vertebrae is taken with the osteotome. After the first rib is cut anteriorly and posteriorly, the surgeon inserts the index finger from one hand in the front and the index finger from the other hand from the back to palpate the tumor (Fig. 67-8) and identify its relationship to the T1 and C8 nerve roots, the lower trunk of the brachial plexus, and the axillary subclavian artery and vein (Fig. 67-9). The scalenus anticus and medius muscles are divided with the finger holding the en bloc section anteriorly and inferiorly. Caution is taken to avoid injury to the artery or vein. The T1 nerve root is divided posteriorly, and the segment is lifted up with the tumor. The C8 nerve root is visualized and may be divided if necessary. The anterior part of the T1 nerve root is divided. The subclavian artery is dissected from the tumor. If the artery is involved, an interposition graft, such as autogenous saphenous vein, is used. This is usually not the case because the adventitia protects the artery from tumor invasion.
A lobectomy or segmental resection of the lung is performed after the en bloc chest wall resection. The chest wall is closed with Marlex if anterior in location. For posterior tumors, however, the scapula covers the posterior area, and usually no chest wall reconstruction is necessary (Fig. 67-10). If the fifth rib is removed, the scapula tip may get hooked under the sixth rib. If it appears that this may be a possibility, the tip of the scapula is excised (Fig. 67-11). The wound is closed in layers with interrupted 0 Nuralon sutures in a figure-of-eight fashion (Tom Jones stitch), running 2-0 Vicryl in the subcutaneous tissues, and skin clips in the skin.
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COMPLICATIONS OF THERAPY Surgery Surgical morbidity includes bleeding, atelectasis, infection, thromboembolism, persistent air leak, empyema, spinal fluid leak with pneumoencephalogram and meningitis, chylothorax, ulnar nerve paresis or paralysis, and Horner's syndrome not present preoperatively.32 Interestingly enough, taking T1 or even T2 does not seem to produce much of a clinical problem, and even C8 does not give the usual severe problems of ulnar plexus injuries. Possibly this is so because the slow growth of the tumor permits other nerve roots to assume function. Surgical morbidity is 38%, and mortality is between 5% and 10%.33,34 Irradiation Therapy Adverse effects of irradiation therapy include skin fibrosis, fatigue, esophagitis, radiation pneumonitis, pulmonary fibrosis, myelitis, and brachial neuritis, all of which may be extremely devastating to the patient.35 Chemotherapy Complications of chemotherapy include myelosuppression, increased risk of bleeding and infection, peripheral or central neuropathy, renal insufficiency, mucositis, nausea, vomiting, diarrhea, and hypersensitive reaction to secondary malignancies.36 Recurrence There is a significant risk of local or regional recurrence and distant metastases following treatment of superior sulcus tumors, just as there is for any bronchogenic carcinoma. Brain metastasis is one of the most common in younger patients with large cell and adenocarcinoma.37 |
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SUMMARY Pancoast's syndrome is a collection of characteristic symptoms and signs that includes shoulder and arm pain in a specific dermatomal distribution, Horner's syndrome, and weakness and atrophy of the muscles of the hand, most commonly caused by extension of an apical lung tumor located at the superior thoracic inlet. Although most cases are the result of bronchogenic carcinoma, other neoplastic and nonneoplastic causes exist, and a definitive histologic diagnosis should be sought before consideration of treatment options. Treatment should be attempted after careful evaluation of the extent of the disease and the underlying medical status. The most effective treatment of Pancoast's syndrome owing to bronchogenic carcinoma is clearly preoperative irradiation (3000 rads) combined with extended en bloc surgical resection (Table 67-1). Five-year survival for N0 stage I disease is 35%. The exact role of adjuvant and neoadjuvant systemic chemotherapy is not established at this time. Preliminary reports with preoperative chemoradiotherapy followed by surgical resection show that this approach is feasible and may be associated with similar survival. Whenever possible, patients with Pancoast's tumors should be enrolled in prospective clinical trials so that we can add to our knowledge about this disease and determine the most effective and optimal therapy.
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EDITOR'S COMMENT This classic chapter described by one of the world's experts in the field, provides an overview of superior sulcus tumors both from an oncological and technical perspective. Although generally treated with a combination of radiation and surgery, we currently routinely approach these lesions with neoadjuvant chemoradiation followed by surgical resection. The standard posterior Paulson/Shaw approach is described. –MJK |
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REFERENCES
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