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Chemotherapeutic agents are used to treat this disease. Fewer than 5% of patients require pulmonary resection as part of their therapeutic regimen, and this is usually performed after a course of chemotherapy.

Indications for surgery

Bronchopleural fistula with empyema

Destroyed lobe or lung

Persistent open cavities with positive sputum

Post -tubercular bronchial stenosis

Pulmonary hemorrhage

Suspected carcinoma

Aspergilloma

Bronchiectasis

IV Solitary Pulmonary Nodules (Coin Lesions)

Solitary pulmonary nodules are well-circumscribed, peripheral nodules that are manifestations of neoplastic disease (e.g., bronchogenic carcinoma) or of granulomatous or infectious processes (e.g., fungus or tuberculosis).

A General characteristics

Solitary pulmonary nodules are usually asymptomatic.

They occur more often in men than in women.

B Benign versus malignant etiology

When no other tumor is known to be present, the solitary pulmonary nodule is rarely a sign of metastatic disease.

If the patient is younger than 40 years of age, there is a two-thirds chance that the lesion is benign.

The likelihood of cancer is higher in men than in women.

Radiographic evidence of a benign lesion includes the following:

Calcification is present, particularly concentric, heavy, or popcornlike calcification (if the calcification appears as small flecks, a malignant lesion should be suspected).

Radiographs taken at least 2 years apart show no growth in the size of the lesion.

The lesion's size is less than 1 cm in diameter. (The larger the lesion, the greater is the chance of a malignancy.)

CT scan demonstrates a well-circumscribed lesion. (Multiple lesions that are demonstrated on a CT scan but are not seen on plain film suggest either metastatic disease or satellite lesions from

carcinoma or granulomas.) There is no advantage of MRI over a CT scan for imaging of solitary pulmonary nodes.

Because no radiographic characteristic other than dense calcification absolutely indicates a benign lesion, tissue biopsy is mandatory for diagnosis.

V Bronchogenic Carcinoma

AOverview

Incidence

Bronchogenic carcinoma is the leading cause of cancer death in the United States.

Approximately 180,000 new cases are diagnosed each year in the United States.

About 95% of lung cancers occur in patients who are older than 40 years of age.

Etiology

Ninety-five percent of all lung carcinomas are related to smoking; affected individuals usually have a history of smoking one or more packs of cigarettes daily for 20 years.

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There is no known environmental cause. However, chronic exposure to various substances may play a role; nickel, asbestos, arsenic, radioactive materials, and petroleum products have all been implicated.

B Pathology

Adenocarcinoma is now the most common lung carcinoma , representing 30%–45% of all malignant lung cancers. It is less strongly associated with smoking and occurs more commonly in women.

Histology reveals distinct acinar formation of cells, which arise from the subsegmental airways in the periphery of the lung.

Characteristics

Many of these tumors are formed in conjunction with lung scars, representing a response to chronic irritation.

Growth may be slow, but the cancer metastasizes readily by a vascular route. It may spread diffusely throughout the lung via the tracheobronchial tree.

Variants. Bronchoalveolar carcinoma is a variant of adenocarcinoma, which represents a highly differentiated form that spreads along alveolar walls.

Its three forms consist of a solitary nodule, a multinodular form, and a diffuse/pneumonic form.

It has the best prognosis of all the cell types.

Squamous cell carcinoma is the second most common carcinoma of the lung, representing 25%–40% of all malignant tumors. It is associated with smoking.

Pulmonary symptoms include cough, dyspnea, chest pain, fever, sputum production, and wheezing. Patients may be asymptomatic, which is the only clue to the cancer producing an abnormal chest radiograph.

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Extrapulmonary symptoms

Metastatic extrapulmonary manifestations include weight loss, malaise, symptoms referable to the central nervous system, and bone pain.

Nonmetastatic extrapulmonary manifestations (paraneoplastic syndromes) are secondary to hormonelike substances that are elaborated by the tumor. These include Cushing's syndrome, hypercalcemia, myasthenic neuropathies, hypertrophic osteoarthropathies, and gynecomastia.

Pancoast's tumor, which involves the superior sulcus, may produce symptoms related to brachial plexus involvement, sympathetic ganglia involvement, or vertebral collapse secondary to local invasion. This may result in pain or weakness of the arm, edema, or Horner's syndrome (i.e., ptosis, miosis, enophthalmos, and anhidrosis).

D Diagnosis and staging

Abnormal chest radiograph is the most common finding.

The tumor may present as a nodule, an infiltrate, or as atelectasis.

An abnormal chest radiograph is more likely to represent carcinoma in patients older than 40 years of age.

CT scan reveals the extent of the tumor and the possibility of mediastinal lymph node metastasis.

Positron emission tomography (PET) scan is routinely used to assess the primary tumor, the mediastinal lymph nodes, and to screen for metastatic disease.

Bronchoscopy assesses for bronchial involvement and resectability in central lesions, and tissue is obtained for cytologic examination.

Mediastinoscopy or mediastinotomy obtains mediastinal lymph nodes for pathologic examination and aids in the staging of the disease. Positive findings may or may not preclude a curative resection, depending on the pathologic cell type, the extent of nodal involvement, and the condition of the patient.

Percutaneous needle biopsy may be used for peripheral lesions to obtain tissue for cytologic examination.

E

Staging of lung carcinoma is fundamental for the evaluation of treatment protocols (Table 5-1). It is based on information obtained during the preoperative evaluation, findings at mediastinoscopy (see V D 4), thoracotomy, and pathologic findings of the surgical specimens. Definitions of tumor size (T), lymph node metastasis (N), and distant metastasis (M) comprise the TNM classification of carcinoma of the lung by the revised International Clinical Staging System.

TABLE 5-1 Stage Grouping in Cancer of the Lung

T, tumor size; N, lymph node metastasis; M, distant metastasis.

Reprinted with permission from the American Joint Committee for Cancer Staging (AJCC), 1998.

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T (primary tumors)

TX: The tumor is proved by the presence of malignant cells in bronchopulmonary secretions but is not visualized on a radiograph or by bronchoscopy, or any tumor that cannot be assessed, such as one in a retreatment staging.

T0: No evidence of primary tumor

TIS: Carcinoma in situ

T1: A tumor that is 3 cm or less in greatest dimension, surrounded by lung or visceral pleura and with no evidence of invasion proximal to a lobar bronchus at bronchoscopy

T2: A tumor more than 3 cm in greatest dimension or a tumor of any size that either invades the visceral pleura or has associated atelectasis or obstructive pneumonitis that extends to the hilar region. At bronchoscopy, the proximal extent of demonstrable tumor must be within a lobar bronchus or at least 2 cm distal to the carina. Any associated atelectasis or obstructive pneumonitis must involve less than an entire lung.

T3: A tumor of any size with direct extension into the chest wall (including superior sulcus tumors), diaphragm, mediastinal pleura, or pericardium without involving the heart, great vessels, trachea, esophagus, or vertebral body or a tumor in the main bronchus within 2 cm of the carina without involving the carina

T4: A tumor of any size with invasion of the mediastinum or involving the heart, great vessels, trachea, esophagus, vertebral body, or carina or the presence of malignant pleural effusion. In addition, satellite tumor nodules can occur within the ipsilateral primary tumor lobe of the lung.

N (nodal involvement)

N0: No demonstrable metastasis to regional lymph nodes

N1: Metastasis to lymph nodes in the peribronchial or the ipsilateral hilar region, or both, including direct extension

N2: Metastasis to ipsilateral mediastinal lymph nodes and subcarinal lymph nodes

N3: Metastasis to contralateral mediastinal lymph nodes, contralateral hilar lymph nodes, ipsilateral or contralateral scalene or supraclavicular lymph nodes

M (distant metastasis)

M0: No (known) distant metastasis

M1: Distant metastasis present or separate metastatic tumor nodules in the ipsilateral nonprimary tumor lobes of the lung.

F Treatment

Surgical treatment

Pulmonary resection (i.e., lobectomy, extended lobectomy, or pneumonectomy) is the only potential cure for bronchogenic carcinoma. The surgical approach is to resect the involved lung, regional lymph nodes, and involved contiguous structures, if necessary.

Lobectomy is used in disease localized to one lobe.

Extended resections and pneumonectomy are used when the tumor involves a fissure or is close to the pulmonary hilus.

Wedge resections or bronchial segmentectomy may be used in localized disease in high-risk patients.

Contraindications for thoracotomy. One half of all patients with lung carcinomas are not candidates for thoracotomy at the time of diagnosis.

Extensive ipsilateral mediastinal lymph node involvement (N2 disease), particularly high paratracheal and subcarinal

Any contralateral mediastinal lymph node involvement (N3 disease)

Distant metastases

Malignant pleural effusion

Superior vena cava syndrome

Recurrent laryngeal nerve involvement

Phrenic nerve paralysis

Poor pulmonary function (relative contraindication)

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Adjuvant therapy. Further treatment using radiotherapy, chemotherapy, or both is indicated for some advanced -stage tumors.

Postoperative adjuvant chemotherapy is now indicated in all resected nonsmall cell lung cancer patients Stage Ib and higher, demonstrating a small but statistically significant survival benefit.

Preoperative chemotherapy (with or without radiation therapy) in patients with stage IIIa (N2) disease has been used in an attempt to convert advanced local disease into a resectable lesion. However, the efficacy of this therapy has yet to be determined, although early results appear promising.

G

Prognosis depends primarily on cell types and on the stage of disease at the time of diagnosis.

Five-year survival based on cell type

Bronchoalveolar carcinoma, 30%–35%

Squamous cell carcinoma, 8%–16%

Adenocarcinoma, 5%–10%

Small cell carcinoma, <3%

Five-year survival based on postoperative pathologic stage

Stage I, 60%–80%

Stage II, 40%–55%

Stage IIIa, 10%–35%

VI Bronchial Adenomas

The term adenoma is an unfortunate misnomer because these lesions are all malignant neoplasms, albeit relatively low grade in character. They arise from the epithelium, ducts, and glands of the tracheobronchial tree and include the carcinoid tumor, adenoid cystic carcinoma (cylindroma), and mucoepidermoid carcinoma.

A

Carcinoid tumors which comprise 80%–90% of bronchial adenomas, occur mainly in the proximal bronchi (20% main stem bronchi, 60% lobar or segmental bronchi, and 20% peripheral parenchyma).

Characteristics

Characteristics

The location and distribution in the tracheobronchial tree are similar to those found with carcinoid tumors

High-grade and low -grade variants exist, although the latter type predominates.

Treatment principles that are outlined for carcinoid tumors apply to low -grade mucoepidermoid carcinoma. High-grade variants should be approached and managed like other bronchial carcinomas.

VII Hamartomas

A Pathology

These pulmonary tumors are benign and are classified histologically as adenochondromas. They occur within the substance of the lung and usually present as solitary pulmonary nodules.

B

Treatment involves removal during a diagnostic thoracotomy for evaluation of the solitary nodule.

VIII Metastatic Tumor

A

Metastatic tumors are common to the lung, which may be the only site of metastases from a nonpulmonary primary tumor.

B Treatment

Single or multiple metastatic tumors can be removed from the lung as part of the treatment protocol (Table 5-2).

The best treatment results are obtained with metastatic tumors that can be completely resected and in those patients with less than three to five metastatic nodules.

TABLE 5-2 Common Metastatic Pulmonary Tumors

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IX Disorders of the Trachea

AAnatomy

Structure

The trachea is 11 cm from the cricoid to the carina with a range in the adult of about 10–13 cm in length and 1.8–2.3 cm in diameter.