PART II
Specific Considerations
CHAPTER 19
Chest Wall, Lung, Mediastinum, and Pleura
BASIC SCIENCE QUESTIONS
1. What is the approximate length of the trachea distal to the subglottic space?
A. 7-8 cm
B. 10-13 cm
C. 14-16 cm
D. 20-24 cm
Answer: B
The trachea is composed of cartilaginous and membranous portions, beginning with the cricoid cartilage, the first complete cartilaginous ring of the airway. The cricoid cartilage consists of an anterior arch and a posterior broad-based plate. Articulating with the posterior cricoid plate are the arytenoid cartilages. The vocal cords originate from the arytenoid cartilages and then attach to the thyroid cartilage. The subglottic space, the narrowest part of the trachea with an internal diameter of approximately 2 cm, begins at the inferior surface of the vocal cords and extends to the first tracheal ring. The remainder of the distal trachea is 10.0 to 13.0 cm long, consists of 18 to 22 rings, and has an internal diameter of 2.3 cm. (See Schwartz 9th ed., p 514.)
2. The lymphatic drainage from the pulmonary (N1) nodes of the lung terminates in the lymphatic sump of Borrie which, on the right side, is located
A. Around the bronchus intermedius
B. In the intralobar fissure
C. In the posterior mediastinum
D. At the level of the carina
Answer: A
Lymph nodes that drain the lungs are divided into two groups according to the tumor, node, and metastasis (TNM) staging system for lung cancer: the pulmonary lymph nodes, N1; and the mediastinal nodes, N2 (Fig. 19-1).
The N1 lymph nodes consist of the following: (a) intra-pulmonary or segmental nodes that lie at points of division of segmental bronchi or in the bifurcations of the pulmonary artery; (b) lobar nodes that lie along the upper, middle, and lower lobe bronchi; (c) interlobar nodes that are located in the angles formed by the bifurcation of the main bronchi into the lobar bronchi; and (d) hilar nodes that are located along the main bronchi. The interlobar lymph nodes lie in the depths of the interlobar fissure on each side and constitute a lymphatic sump for each lung, referred to as the lymphatic sump of Borrie; all of the pulmonary lobes of the corresponding lung drain into this group of nodes (Fig. 19-2). On the right side, the nodes of the lymphatic sump lie around the bronchus intermedius (bounded above by the right upper lobe bronchus and below by the middle lobe and superior segmental bronchi). On the left side, the lymphatic sump is confined to the interlobar fissure, with the lymph nodes in the angle between the lingular and lower lobe bronchi and in apposition to the pulmonary artery branches. (See Schwartz 9th ed., p 520.)
FIG. 19-1. The location of regional lymph node stations for lung cancer staging. Station, Description: 1, highest mediastinal lymph nodes; 2, upper paratracheal nodes; 3, prevascular, precarinal, and retrotracheal nodes; 4, lower paratracheal nodes; 5, aorto-pulmonary nodes; 6, pre-aortic nodes; 7, subcarnal nodes; 8, paraesophageal nodes; 9, pulmonary ligament nodes; 10, tracheobronchial nodes; 11, interlobular nodes; 12, lobar bronchial nodes; 13, segmental nodes; 14, subsegmental nodes. Note: Stations 12, 13, and 14 are not shown in their entirety. (Reproduced with permission from Ferguson, MK: Thoracic Surgery Atlas. W.B. Saunders, Inc., Philadelphia, PA, 2007. Copyright © Elsevier.)
FIG. 19-2. The lymphatic sump of Borrie includes the groups of lymph nodes that receive lymphatic drainage from all pulmonary lobes of the corresponding lung.
3. Which of the following genes is associated with desmoid tumors of the chest wall?
A. p53
B. BRAC-2
C. Adenomatous polyposis coli (APC)
D. HER2
Answer: C
Desmoid tumors have recently been shown to possess alterations in the adenomatous polyposis coli/β-catenin pathway, and cyclin D1 dysregulation is thought to play a significant role in their pathogenesis. Associations with other diseases and conditions are well documented, especially those with similar alterations in the adenomatous polyposis coli pathway, such as familial adenomatous polyposis (Gardner’s syndrome). (See Schwartz 9th ed., p 565.)
4. How many segments are in the left lung?
A. 7
B. 8
C. 9
D. 10
Answer: C
There are 9 segments in the left lung and 10 segments in the right lung. (See Schwartz 9th ed., p 520, and Fig. 19-3).
FIG. 19-3. Segmental anatomy of the lungs and bronchi.
CLINICAL QUESTIONS
1. The most appropriate treatment for clinically significant tracheal stenosis is
A. Endoscopic balloon dilation
B. Endoscopic placement of a wire stent
C. Laser ablation
D. Resection and primary anastomosis
Answer: D
The treatment of tracheal stenosis is resection and primary anastomosis. In nearly all postintubation injuries the injury is transmural, and significant portions of the cartilaginous structural support are destroyed (Fig. 19-4). Measures such as laser ablation are temporizing. In the early phase of evaluating patients, dilation using a rigid bronchoscope is useful to gain immediate relief of dyspnea and to allow full assessment of the lesion. It is important to carefully document the length and position of the stenosis as well as the location in relation to the vocal cords. Rarely, if ever, is a tracheostomy necessary. For patients who are not operative candidates due to associated comorbidities, internal stents, typically silicone T tubes, are useful. Wire mesh stents should not be used, given their known propensity to erode through the wall of the airway. The use of balloon dilation and tracheoplasty also has been described, although their efficacy is marginal. Efforts focused on tissue engineering may provide suitable material for tracheal replacement in long-segment tracheal stenosis in the future.
Most intubation injuries are located in the upper third of the trachea, so tracheal resection usually is done through a collar incision. Resection typically involves 2 to 4 cm of trachea for benign stenosis. However, a primary anastomosis can still be performed without undue tension, even if up to one half of the trachea needs to be resected. When resection for a postintubation injury is performed, it is critical to fully resect all inflamed and scarred tissue. Tracheostomies and stents are not required postoperatively, and the patient often is extubated in the operating room or shortly thereafter. (See Schwartz 9th ed., pp 516-517.)
FIG. 19-4. Diagram of the principal postintubation lesions. A. A circumferential lesion at the cuff site after the use of an endotracheal tube. B. Potential lesions after the use of tracheostomy tubes. Anterolateral stenosis can be seen at the stomal level. Circumferential stenosis can be seen at the cuff level (lower than with an endotracheal tube). The segment in between is often inflamed and malacotic. C. Damage to the subglottic larynx. D. Tracheoesophageal fistula occurring at the level of the tracheostomy cuff. Circumferential damage is usual at this level. E. Tracheoinnominate artery fistula. (Adapted with permission from Grillo HC: Surgical treatment of postintubation tracheal injuries. J Thorac Cardiovasc Surg 8:860, 1979.)
2. Which of the following is an indication for drainage of a peri-pneumonic effusion?
A. pH 7.20
B. Glucose 60 mg/dL
C. LDH 100 units/L
D. WBC >10,000/dl
Answer: A
The finding of grossly purulent, foul-smelling pleural fluid makes the diagnosis of empyema obvious on visual examination at the bedside. In the early stage, small to moderate turbid pleural effusions in the setting of a pneumonic process may require further pleural fluid analysis. Close clinical follow-up also is imperative to determine if progression to empyema is occurring. A deteriorating clinical course or a pleural pH of 7.20 and a glucose level of 40 mg/dL indicates the need to drain the fluid.
As organisms enter the pleural space, an influx of polymorphonuclear cells occurs, with a subsequent release of inflammatory mediators and toxic oxygen radicals. In attempting to control the invading organisms, these mechanisms lead to variable degrees of endothelial injury and capillary instability. An influx of fluid into the pleural space then occurs, followed by a process that overwhelmsthe normal exit avenues of the pleural lymphatic network. This early effusion is watery and free flowing in the pleural cavity. Thoracentesis at this stage yields fluid with a pH typically >7.3, a glucose level of >60 mg/dL, and a low LDH level (500 units/L). If relatively thin, purulent pleural fluid is found early in the setting of a pneumonic process, the fluid often can be completely drained with simple large-bore thoracentesis. If complete lung expansion is obtained and the pneumonic process is responding to antibiotics, no further drainage may be necessary. A finding of pleural fluid with a pH 7.2 and with a low glucose level means that a more aggressive approach to drainage should be pursued. (See Schwartz 9th ed., pp 579-580.)
3. A 55–year-old nonsmoker is noted to have a solitary pulmonary nodule on plain radiograph. Based on the CT finding in Fig. 19-5, what is the most likely diagnosis for this patient?
FIG. 19-5.
A. Benign neoplasm
B. Malignant neoplasm
C. Granulomatous nodule
D. Hamartoma
Answer: B
This CT shows a solitary pulmonary nodule with a corona radiata sign. Irregular, lobulated, or speculated edges strongly suggest malignancy. The corona radiata sign (consisting of fine linear strands extending 4 to 5 mm outward and appearing spiculated on radiographs) is highly cancer specific. (See Schwartz 9th ed., p 527.)
4. Lung cancer in a patient who has never smoked is most likely to be
A. Large cell carcinoma
B. Adenocarcinoma
C. Squamous cell carcinoma
D. Bronchoalveolar carcinoma
Answer: B
Approximately 25% of all lung cancers worldwide and 53% of cancers in women are not related to smoking, and the majority of these (62%) are adenocarcinomas. (See Schwartz 9th ed., p 529.)
5. A patient with a primary tracheal tumor is found on bronchoscopy to have a sessile tumor with extensive submucosal infiltration. The most likely diagnosis is
A. Adenocarcinoma
B. Squamous cell carcinoma
C. Adenoid cystic carcinoma
D. Small cell carcinoma
Answer: C
Squamous cell carcinomas of the trachea often present with regional lymph node metastases and are frequently not resectable at the time of presentation. Their biologic behavior is similar to that of squamous cell carcinomas of the lung. Adenoid cystic carcinomas, which are a type of salivary gland tumor, are generally slow growing, spread submucosally, and tend to infiltrate along nerve sheaths and within the tracheal wall. Spread to regional lymph nodes can occur. Although indolent in nature, adenoid cystic carcinomas are malignant and can spread to the lungs and bones. Squamous cell carcinomas and adenoid cystic carcinomas represent approximately 65% of all tracheal neoplasms. The remaining 35% is composed of small cell carcinomas, mucoepidermoid carcinomas, adenocarcinomas, lymphomas, and others. (See Schwartz 9th ed., p 519.)
6. The treatment of choice for a patient with a Pancoast tumor, no metastases, and good pulmonary function is
A. Surgical resection followed by radiation therapy
B. Surgical resection followed by chemotherapy and radiotherapy
C. Induction chemotherapy followed by surgical resection
D. Induction chemotherapy and radiotherapy followed by surgical resection
Answer: D
Carcinoma arising in the extreme apex of the chest with associated arm and shoulder pain, atrophy of the muscles of the hand, and Horner syndrome was first described by Henry Pancoast in 1932. Any tumor of the superior sulcus, including tumors without evidence of involvement of the neurovascular bundle, is now commonly known as Pancoast’s tumor. The designation should be reserved for those tumors involving the parietal pleura or deeper structures overlying the first rib. Chest wall involvement at or below the second rib should not be considered Pancoast’s tumor. Treatment involves a multidisciplinary approach. Goals of operative treatment obviously include curative resection; however, due to the location of the tumor and involvement of the neurovascular bundle that supplies the ipsilateral extremity, preserving postoperative function of the extremity also is critical.
Historically, Pancoast’s tumors have been difficult to treat, with high rates of local recurrence and poor 5-year survival with radiation and/or surgical resection. Tumor invasion into surrounding structures prompted investigations into modalities such as induction radiation and, more recently, concomitant radiation and chemotherapy, to improve rates of complete resection. The Southwest Oncology Group formally studied the use of induction chemoradiotherapy followed by surgery, and long-term results are now available. The treatment regimen was well tolerated, with 95% of patients completing induction treatment. Complete resection was achieved in 76%. Five-year survival was 44% overall and 54% when complete resection was achieved. Disease progression with this regimen was predominantly at distant sites, with the brain being the most common. A treatment algorithm for Pancoast’s tumors is presented in Fig. 19-6. (See Schwartz 9th ed., pp 544-545.)
FIG. 19-6. Treatment algorithm for Pancoast’s tumors. CT = computed tomography; MRA = magnetic resonance angiography; MRI = magnetic resonance imaging; NSCLC = non–small cell lung cancer; PET = positron emission tomography.
7. When compared to open thoracotomy, VATS (video-assisted thoracic surgery) has been shown to result in
A. Reduced mortality
B. Slower recovery of respiratory function
C. Faster return to work
D. Decreased ability to tolerate chemotherapy
Answer: C
Thoracic surgical approaches have changed over recent years with advancements in minimally invasive approaches. A surgeon trained in advanced minimally invasive techniques can now perform sympathectomy, segmental lung resections, lobectomies, and mediastinal resections through multiple thoracoscopic ports and small access incisions without the need for a substantial, rib-spreading incision. Although there has not been a documented change in mortality using these approaches, subjective measures of quality of life after video-assisted thoracic surgery (VATS), such as pain level and perceived functional recovery, consistently and reproducibly favor VATS over thoracotomy. Objective measures such as functional status as measured by 6-minute walk, return to work, and ability to tolerate chemotherapy also favor VATS over thoracotomy. Finally, recovery of respiratory function occurs earlier in patients undergoing VATS. These findings are pronounced in patients with chronic obstructive pulmonary disease (COPD) and in the elderly, populations whose quality of life can be dramatically impacted by changes in their respiratory symptoms and function, thoracic pain, and physical performance. (See Schwartz 9th ed., p 522.)
8. If the pleural space is altered by disease processes such as malignant effusion or pleural space infections or following pleurodesis, chest tubes must remain in place until the drainage is
A. 50 ml/24 hrs or less
B. 150 ml/24 hrs or less
C. 400 ml/24 hrs or less
D. 750 ml/24 hrs or less
Answer: B
The tube is removed when the air leak is resolved and when the volume of drainage decreases below an acceptable level over 24 hours. The ideal volume of drainage over a 24-hour period that predicts safe chest tube removal is unknown. The ability of the pleural lymphatics to absorb fluid is substantial. It can be as high as 0.40 mL/kg per hour in a healthy individual, possibly resulting in the absorption of up to 500 mL of fluid over a 24-hour period. The capacity of the pleural space to manage and absorb fluid is high if the pleural lining and lymphatics are healthy. In the past, many surgeons required a drainage volume of 150 mL over 24 hours before removing a chest tube. Recently, however, it has been shown that pleural tubes can be removed after VATS lobectomy or thoracotomy with 24-hour drainage volumes as high as 400 mL without subsequent development of pleural effusions. Currently, it is the practice of these authors to remove chest tubes when 24-hour output is ≤400 mL after lobectomy or lesser pulmonary resections.
If the pleural space is altered (e.g., malignant pleural effusion, pleural space infections or inflammation, or pleurodesis), strict adherence to a volume requirement before tube removal is appropriate (typically 100 to 150 mL over 24 hours). Such circumstances alter normal pleural fluid dynamics. (See Schwartz 9th ed., p 524.)
9. Patients with Lambert-Eaton syndrome who remain symptomatic following treatment of their primary malignancy are best treated by
A. Neostigmine
B. Guanidine hydrochloride
C. Anti IgA monoclonal antibodies
D. Cyclosporine
Answer: B
Lambert-Eaton syndrome is a myasthenia-like syndrome usually seen in patients with SCLC. It is caused by a neuromuscular conduction defect. Gait abnormalities are due to proximal muscle weakness and fatigability, and particularly affect the thighs. Symptoms can occur before symptoms of the primary tumor and may actually precede radiographic evidence of the tumor. The syndrome is produced by immunoglobulin G antibodies targeting voltage-gated calcium channels, which function in the release of acetylcholine from presynaptic sites at the motor end plate. Therapy is directed at the primary tumor with resection, radiation, and/or chemotherapy. Many patients have dramatic improvement after resection or successful medical therapy. For patients with refractory symptoms, treatment consists of administration of guanidine hydro-chloride, immunosuppressive agents such as prednisone and azathioprine, and occasionally plasma exchange. Unlike in myasthenia gravis patients, neostigmine is usually ineffective. (See Schwartz 9th ed., p 536.)
10. Which of the following chest wall sarcomas is most likely to respond to preoperative chemotherapy?
A. Fibrosarcoma
B. Malignant fibrous histiocytoma
C. Synovial sarcoma
D. Primitive neuroectodermal tumor
Answer: D
Sarcomas can be divided into two broad groups according to potential responsiveness to chemotherapy (Table 19-1). Preoperative (neoadjuvant) chemotherapy offers the ability to (a) assess tumor chemosensitivity by the degree of tumor size reduction and microscopic necrosis, (b) determine to which chemotherapeutic agents the tumor is sensitive, and (c) lessen the extent of surgical resection by reducing tumor size. Patients whose tumors are responsive to preoperative chemotherapy (as judged by the reduction in the size of the primary tumor and/or by the degree of necrosis seen histologically after resection) have a much better prognosis than those whose tumors show a poor response. (See Schwartz 9th ed., p 565.)
TABLE 19-1 Classification of sarcomas by therapeutic response
11. What percent of the trachea can be safely resected?
A. 20%
B. 30%
C. 40%
D. 50%
Answer: D
The length limit of tracheal resection is roughly 50% of the trachea. To prevent tension on the anastomosis postoperatively, specialized maneuvers are necessary, such as anterolateral tracheal mobilization, suturing of the chin to the sternum with the head flexed forward for 7 days, laryngeal release, and right hilar release. For most tracheal resections (which involve much less than 50% of the airway), anterolateral tracheal mobilization and suturing of the chin to the sternum for 7 days are done routinely. Use of laryngeal and hilar release is determined at the time of surgery, based on the surgeon’s judgment of the degree of tension present. (See Schwartz 9th ed., p 519.)
12. Which of the following mediastinal masses is most likely to be found in the anterior mediastinum?
A. Pleuropericardial cyst
B. Ganglioneuroma
C. Pheochromocytoma
D. Germ cell tumor
Answer: D
(See Schwartz 9th ed., p 570, and Table 19-2.)
TABLE 19-2 Usual location of the common primary tumors and cysts of the mediastinum
13. The primary treatment for oat cell carcinoma of the lung is
A. Surgery followed by chemotherapy
B. Chemotherapy alone
C. Chemotherapy and radiation therapy
D. Immunotherapy
Answer: C
Small cell lung carcinoma (SCLC) accounts for approximately 20% of primary lung cancers and generally is not treated surgically. These aggressive neoplasms have early, widespread metastases. Histologically, they can be difficult to distinguish from lymphoproliferative lesions and atypical carcinoid tumors. Therefore, a definitive diagnosis must be established with adequate tissue samples. Three groups of SCLC are recognized: pure small cell carcinoma (sometimes referred to as oat cell carcinoma), small cell carcinoma with a large cell component, and combined (mixed) tumors. Unlike with NSCLC, the clinical stage of SCLC is defined broadly by the presence of either local “limited” or distant “disseminated” disease. SCLC presenting with bulky locoregional disease but no evidence for distant metastatic disease is termed limited SCLC. Most often, the primary tumor is large and associated with bulky mediastinal adenopathy, which may lead to obstruction of the superior vena cava. SCLC falling into the other clinical stage, termed disseminated, usually presents with metastatic disease throughout the patient’s body. Regardless of the stage of presentation, treatment is primarily chemotherapy and radiation. Surgery is appropriate for the rare patient with an incidentally discovered peripheral nodule that is found to be SCLC. If a stage I SCLC is identified after resection, postoperative chemotherapy usually is given. (See Schwartz 9th ed., pp 548-549.)
14. A 65-year-old who has smoked 2 packs a day for 45 years is found to have a 2-cm solitary pulmonary nodule 1 cm from the surface of the superior segment of the right lower lobe. The best initial diagnostic procedure is
A. Observation with biopsy if this increases in size over 3-6 months
B. Bronchoscopy
C. Fine-needle aspiration
D. Open thoracotomy for excisional biopsy
Answer: C
The surgeon must have an evidence-based algorithm for approaching the diagnosis and treatment of a pulmonary nodule. Guidelines have been developed based on a systematic literature review and consensus of clinical experts in the field (Fig. 19-7). Only through biopsy can a pulmonary nodule be definitively diagnosed. Bronchoscopy has a 20 to 80% sensitivity for detecting a neoplastic process within a solitary pulmonary nodule, depending on the nodule size, its proximity to the bronchial tree, and the prevalence of cancer in the population being sampled. Transthoracic fine-needle aspiration (FNA) biopsy can accurately identify the status of peripheral pulmonary lesions in up to 95% of patients; the false-negative rate ranges from 3 to 29%. Complications may occur at a relatively high rate (e.g., a 30% rate of pneumothorax). VATS often is used for excising and diagnosing indeterminate pulmonary nodules. Lesions most suitable for VATS are those that are located in the outer one third of the lung and those that are 3 cm in diameter. Certain principles must be followed when excising potentially malignant lesions via VATS. The nodule must not be directly manipulated with instruments, the visceral pleura overlying the nodule must not be violated, and the excised nodule must be extracted from the chest within a bag to prevent seeding of the chest wall. Some groups advocate proceeding directly to VATS in the work-up of a solitary pulmonary nodule in appropriate clinical circumstances, citing superior diagnostic accuracy and low surgical risks. (See Schwartz 9th ed., pp 527-528.)
FIG. 19-7. Recommended management algorithm for patients with solitary pulmonary nodules (SPNs) measuring 8 mm to 30 mm in diameter. CT = computed tomography; CXR = chest radiograph; PET = positron emission tomography; XRT = radiotherapy. (Adapted from Ost D, Fein AM, Feinsilver SH. Clinical practice: the solitary pulmonary nodule. N Engl J Med 2003; 348:2535–2542.)
15. What is the probability that a solitary pulmonary nodule is malignant in a patient whose smoke exposure is unknown?
A. 0-20%
B. 20-40%
C. 40-60%
D. >60%
Answer: B
The differential diagnosis of a solitary pulmonary nodule can be distilled down to a differentiation between malignancy and other numerous benign conditions. Ideally, diagnostic approaches would provide a clear distinction between the two, so that definitive surgical resection could be reserved for the malignant nodule and resection avoided when the nodule is benign. In unselected patient populations, a new solitary pulmonary nodule observed on a chest radiograph has a 20 to 40% likelihood of being malignant, with the risk approximately 50% or higher in smokers. (See Schwartz 9th ed., pp 526-527.)
16. The most common mediastinal mass in children is
A. Lymphoma
B. Neurogenic tumor
C. Congenital cyst
D. Germ cell tumor
Answer: B
The most common mediastinal masses in both children and adults are neurogenic tumors, although cysts and thymomas are almost equally common in adults. (See Schwartz 9th ed., p 570, Tables 19-3and 19-4).
TABLE 19-3 Mediastinal tumors in adults
TABLE 19-4 Mediastinal tumors in children
17. A patient with lung cancer who presents with chest wall pain is most likely to have
A. Squamous cell carcinoma
B. Small cell carcinoma
C. Adenocarcinoma
D. Bronchoalveolar carcinoma
Answer: C
Squamous cell and small cell carcinomas frequently arise in main, lobar, or first segmental bronchi, which are collectively referred to as the central airways. Symptoms of airway irritation or obstruction are common and include cough, hemoptysis, wheezing (due to high-grade airway obstruction), dyspnea (due to bronchial obstruction with or without postobstructive atelectasis), and pneumonia (caused by airway obstruction with secretion retention and atelectasis).
In contrast, adenocarcinomas often are located peripherally. For this reason, they are often discovered incidentally as an asymptomatic peripheral lesion on chest radiograph. When symptoms occur, they are due to pleural or chest wall invasion (pleuritic or chest wall pain) or pleural seeding with malignant pleural effusion.
BAC (a variant of adenocarcinoma) may present as a solitary nodule, as multifocal nodules, or as a diffuse infiltrate mimicking an infectious pneumonia (pneumonic form). In the pneumonic form, severe dyspnea and hypoxia may occur, sometimes with expectoration of large volumes (over 1 L/d) of light tan fluid, with resultant dehydration and electrolyte imbalance. Because BAC tends to fill the alveolar spaces as it grows (as opposed to the typical invasion, destruction, and compression of lung architecture seen with other cell types), air bronchograms may be seen radiographically within the tumor. (See Schwartz 9th ed., p 533.)
Peripherally located tumors (often adenocarcinomas) extending through the visceral pleura lead to irritation or growth into the parietal pleura and potentially to continued growth into the chest wall structures. Three types of symptoms are possible, depending on the extent of chest wall involvement: (a) pleuritic pain, from noninvasive contact of the parietal pleura with inflammatory irritation and from direct parietal pleural invasion; (b) localized chest wall pain, with deeper invasion and involvement of the rib and/or intercostal muscles; and (c) radicular pain, from involvement of the intercostal nerve(s). Radicular pain may be mistaken for renal colic in the case of lower lobe tumors that invade the posterior chest wall. (See Schwartz 9th ed., p 534.)
18. What percent of patients with myasthenia gravis and a thymoma will experience improvement or resolution of muscle weakness after resection of the thymoma?
A. 25%
B. 50%
C. 75%
D. 95%
Answer: A
Thymoma is the most frequently encountered neoplasm of the anterior mediastinum in adults (seen most frequently between 40 and 60 years of age). They are rare in children. Most patients with thymomas are asymptomatic, but depending on the institutional referral patterns, between 10 and 50% have symptoms suggestive of myasthenia gravis or have circulating antibodies to acetylcholine receptor. However, 10% of patients with myasthenia gravis are found to have a thymoma on CT. Thymectomy leads to improvement or resolution of symptoms of myasthenia gravis in only approximately 25% of patients with thymomas. In contrast, in patients with myasthenia gravis and no thymoma, thymectomy results are superior: up to 50% of patients have a complete remission and 90% improve. In 5% of patients with thymomas, other paraneoplastic syndromes, including red cell aplasia, hypogammaglobulinemia, systemic lupus erythematosus, Cushing’s syndrome, or syndrome of inappropriate secretion of antidiuretic hormone may be present. Large thymic tumors may present with symptoms related to a mass effect, which may include cough, chest pain, dyspnea, or superior vena caval syndrome. (See Schwartz 9th ed., p 573.)
19. Hypertrophic pulmonary osteoarthropathy
A. Occurs most commonly in patients with bronchoalveolar carcinoma
B. May develop months before patients become symptomatic from a primary malignancy
C. Is best treated by normalizing serum calcium
D. Is most commonly seen in the vertebrae of patients with lung cancer
Answer: B
One of the more common paraneoplastic syndromes in patients with small cell lung cancer (SCLC) is hypertrophic pulmonary osteoarthropathy (HPO). Clinically, the syndrome is characterized by tenderness and swelling of the ankles, feet, forearms, and hands. It is due to periostitis of the fibula, tibia, radius, metacarpals, and metatarsals. Symptoms may be severe and debilitating. Clubbing of the digits occurs with or independently of HPO in up to 30% of patients with SCLC. Symptoms of HPO may antedate the diagnosis of cancer by months. Radiographically, plain films of the affected areas show periosteal inflammation and elevation. A bone scan demonstrates intense but symmetric uptake of radiotracer in the long bones. Relief is afforded by treatment with aspirin or NSAIDs and by successful surgical or medical eradication of the tumor. (See Schwartz 9th ed., p 535.)
20. Surgical intervention in a patient with a lung abscess should be considered
A. If the abscess is >3 cm in diameter
B. If there is no decrease in size after 2 weeks of antibiotic therapy
C. If the abscess is under tension
D. If there are bilateral abscesses
Answer: C
Surgical drainage of lung abscesses is uncommon, because drainage usually occurs spontaneously via the tracheobronchial tree. Indications for intervention are listed in Table 19-5.
External drainage may be accomplished with tube thoracostomy, percutaneous drainage, or surgical cavernostomy. The choice between thoracostomy placement and radiologic placement of a drainage catheter depends on the treating physician’s preference and the availability of interventional radiology. Surgical resection is required in 10% of lung abscess patients. Lobectomy is the preferred intervention for bleeding from a lung abscess or pyopneumothorax. An important intraoperative consideration is to protect the contralateral lung with a double-lumen tube, bronchial blocker, or contralateral main stem intubation. Surgical treatment has a 90% success rate, with an associated mortality of 1 to 13%. (See Schwartz 9th ed., p 551.)
The duration of antimicrobial therapy is variable: 1 to 2 weeks for simple aspiration pneumonia and 3 to 12 weeks for necrotizing pneumonia and lung abscess. It is probably best to treat until the cavity is resolved or until serial radiographs show significant improvement. (See Schwartz 9th ed., p 550.)
TABLE 19-5 Indications for surgical drainage procedures for lung abscesses
|
1. Failure of medical therapy 2. Abscess under tension 3. Abscess increasing in size during appropriate treatment 4. Contralateral lung contamination 5. Abscess >4–6 cm in diameter 6. Necrotizing infection with multiple abscesses, hemoptysis, abscess rupture, or pyopneumothorax 7. Inability to exclude a cavitating carcinoma |
21. Which of the following infections is a significant cause of bronchiectasis?
A. Pneumococcus
B. Nontuberculous mycobacterial infection
C. Rhinovirus
D. Aspergillus
Answer: B
Development of bronchiectasis can be attributed to either congenital or acquired causes. The principal congenital diseases that lead to bronchiectasis include cystic fibrosis, primary ciliary dyskinesia, and immunoglobulin deficiencies (e.g., selective immunoglobulin A deficiency). Congenital causes tend to produce a diffuse pattern of bronchial involvement.
Acquired causes are categorized broadly as infectious and inflammatory. Adenoviruses and influenza viruses are the predominant childhood viral infections associated with the development of bronchiectasis. Chronic infection with tuberculosis remains an important worldwide cause of bronchiectasis.
More significant in the United States are nontuberculous mycobacterial (NTM) infections that cause bronchiectasis, particularly infection by Mycobacterium aviumintracellulare complex. Recently, several studies have suggested an association between chronic gastroesophageal reflux disease, acid suppression, and NTM infection with bronchiectasis. This interaction is thought to be related to chronic aspiration of colonized gastric secretions in the setting of acid suppression. Although a causative relationship has not been proven, these findings suggest a role for gastroesophageal reflux disease in the pathogenesis of this disease process. (See Schwartz 9th ed., pp 551-552.)
22. A mediastinal germ cell tumor with normal alpha- fetoprotein levels and minimally elevated beta-hCG levels is most likely a
A. Teratoma
B. Seminoma
C. Choriocarcinoma
D. Embryonal cell carcinoma
Answer: B
About one third of all primary mediastinal germ cell tumors are seminomatous. Two thirds are nonseminomatous tumors or teratomas. Treatment and prognosis vary considerably within these two groups. Mature teratomas are benign and can generally be diagnosed by the characteristic CT findings of a multilocular cystic tumor encapsulated with combinations of fluid, soft tissue, calcium, and/or fat attenuation in the anterior compartment. FNA biopsy alone may be diagnostic for seminomas, and usually levels of serum markers, including hCG and AFP, are normal. In 10% of seminomas, hCG levels are slightly elevated. FNA findings, along with high hCG and AFP levels, can accurately diagnose nonseminomatous tumors.
Nonseminomatous germ cell tumors include embryonal cell carcinomas, choriocarcinomas, endodermal sinus tumors, and mixed types. They are often bulky, irregular tumors of the anterior mediastinum with areas of low attenuation on CT scan because of necrosis, hemorrhage, or cyst formation. Frequently, adjacent structures have become involved, with metastases to regional lymph nodes, pleura, and lungs. Lactate-dehydrogenase (LDH), AFP, and hCG levels are frequently elevated. (See Schwartz 9th ed., pp 575-576.)
The use of serum markers to evaluate a mediastinal mass can be invaluable in some patients. For example, seminomatous and nonseminomatous germ cell tumors can frequently be diagnosed and often distinguished from one another by the levels of alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCG). In over 90% of nonseminomatous germ cell tumors, either the AFP or the hCG level will be elevated. Results are close to 100% specific if the level of either AFP or hCG is >500 ng/mL. (See Schwartz 9th ed., p 571.)
23. How much protein will be lost per day in a patient with a chylothorax whose chest tube drains 1000 ml/day?
A. 10-15 g
B. 25-50 g
C. 70-85 g
D. 100-120 g
Answer: B
The usual composition of chyle is 2.2 to 5.9 g of protein/100 ml (22-60 g/1000 ml). Therefore, B is the most appropriate answer. (See Schwartz 9th ed., p 582, and Table 19-6.)
TABLE 19-6 Composition of chyle
24. A patient with a chronic draining sinus with yellow granules in the pus most likely has an infection with
A. Aspergillus flavus
B. Nocardia asteroides
C. Actinomyces israelii
D. Cryptococcus neoformans
Answer: C
Actinomycosis is a chronic disease usually caused by Actinomyces israelii. It is characterized by chronic suppuration, sinus formation, and discharge of purulent material containing yellow-brown sulfur granules. Approximately 15% of infections involve the thorax; organisms enter the lungs via the oral cavity (where they normally reside). Because the disease is uncommon, making the correct diagnosis can be challenging, and the clinician must first suspect the disease and then perform appropriate culture analysis under anaerobic conditions. Lung involvement can present with progressive pulmonary fibrosis in the periphery. Pleural and chest wall involvement (periostitis of the ribs) is an associated finding. Treatment consists of prolonged high-dose penicillin, which is very effective. Because of the intense fibrotic reaction surrounding affected parenchyma, surgery is seldom possible.
Aspergillosis can manifest as one of three clinical syndromes: Aspergillus hypersensitivity lung disease, aspergilloma, or invasive pulmonary aspergillosis. Overlap occurs between these syndromes, depending on the patient’s immune status. Hypersensitivity results in productive cough, fever, wheezing, pulmonary infiltrates, eosinophilia, and elevated levels of immunoglobulin E antibodies toAspergillus.
Nocardia asteroides is an aerobic, acid-fast, grampositive organism that usually causes nocardiosis, a disease similar to actinomycosis with additional CNS involvement. In addition, hematogenous dissemination from a pulmonary focus may lead to generalized systemic infection. The disease process ranges from benign, self-limited suppuration of skin and subcutaneous tissues to pulmonary (extensive parenchymal necrosis and abscesses) and systemic (e.g., CNS) manifestations. In immunosuppressed patients, pulmonary cavitation or hematogenous dissemination may be accelerated. Prolonged treatment (2 to 3 months) with sulfadiazine, minocycline, or trimethoprim-sulfamethoxazole is typically required. Surgery to drain abscesses and empyema is indicated.
Cryptococcosis is a subacute or chronic infection caused by Cryptococcus neoformans, a round, budding yeast (5 to 20 µm in diameter) that is sometimes surrounded by a characteristic wide gelatinous capsule. (See Schwartz 9th ed., pp 555-556.)
25. Initial treatment of a patient with massive hemoptysis with airway compromise is
A. Angiography with embolization of the bleeding bronchial artery
B. Rigid bronchoscopy with ice water lavage
C. Rigid bronchoscopy and laser ablation of the bleeding site
D. Thoracotomy with external control of the site of hemorrhage
Answer: B
Massive hemoptysis generally is defined as expectoration of >600 mL of blood within a 24-hour period. It is a medical emergency associated with a mortality rate of 30 to 50%. (See Schwartz 9th ed., p 559.)
Life-threatening bleeding requires emergency airway control and preparation for potential surgery. Such patients are best cared for in an operating room equipped with rigid bronchoscopy equipment. Immediate orotracheal intubation may be necessary to gain control of ventilation and suctioning. However, rapid transport to the operating room and rigid bronchoscopy should be facilitated. Rigid bronchoscopy allows adequate suctioning of bleeding with visualization of the bleeding site; the nonbleeding side can be cannulated with the rigid scope and the patient ventilated. After stabilization, ice-saline lavage of the bleeding site can then be performed (up to 1 L in 50-mL aliquots); bleeding stops in up to 90% of patients.
Alternatively, blockade of the main stem bronchus of the affected side can be accomplished with a double-lumen endotracheal tube, with a bronchial blocker, or by intubation of the nonaffected side using an uncut standard endotracheal tube. Placement of a double-lumen endotracheal tube is challenging in these circumstances, given the bleeding and secretions. Proper placement and suctioning may be difficult, and attempts could compromise the patient’s ventilation. The best option is to place a bronchial blocker in the affected bronchus with inflation. The blocker is left in place for 24 hours and the area is then re-examined bronchoscopically. After this 24-hour period, bronchial artery embolization can be performed. (See Schwartz 9th ed., p 561.)
26. A 2-cm isolated osteochondroma of the rib should be treated by
A. Shave biopsy
B. Local excision
C. Segmental resection of the rib with grossly clear margins
D. Segmental resection of the rib with 2-cm margins
Answer: B
Osteochondromas are the most common benign bone tumor. Many are detected as incidental radiographic findings. Most are solitary. If a patient has multiple osteochondromas, the surgeon must have a high index of suspicion for malignancy, because the incidence of chondrosarcoma is significantly higher in this population.
Osteochondromas occur in the first 2 decades of life, and they arise at or near the growth plate of bones. The lesions are benign during youth or adolescence. Osteochondromas that enlarge after completion of skeletal growth have the potential to develop into chondrosarcomas.
Osteochondromas in the thorax arise from the rib cortex. They are one of several components of the autosomal dominant syndrome known as hereditary multiple exostoses. When part of this syndrome, osteochondromas have a high rate of degeneration into chondrosarcomas. Any patient with hereditary multiple exostoses syndrome who develops new pain at the site of an osteochondroma or who notes gradual growth in the mass over time should be carefully evaluated for osteosarcoma. Local excision of a benign osteochondroma is sufficient treatment. If malignancy is determined, wide excision is performed, with a 4-cm margin. (See Schwartz 9th ed., p 564.)
27. Which of the following preoperative functional assessments is associated with poor outcome after lobectomy or pneumonectomy for resectable lung neoplasm?
A. Predicted postoperative DLCO 70%
B. FEV1 2 L
C. VO2 max 10 mL/kg
D. Unable to walk up 4 flights of stairs
Answer: C
See Fig. 19-8. When obtaining the patient’s history, specific questions should be routinely asked that help determine the amount of lung that the patient will likely tolerate having resected. Can the patient walk on a flat surface indefinitely, without oxygen and without having to stop and rest secondary to dyspnea? If so, the patient will be very likely to tolerate thoracotomy and lobectomy. Can the patient walk up two flights of stairs (up two standard levels), without having to stop and rest secondary to dyspnea? If so, the patient will likely tolerate pneumonectomy. Finally, nearly all patients, except those who show carbon dioxide retention on arterial blood gas analysis, will be able to tolerate periods of single-lung ventilation and wedge resection. (See Schwartz 9th ed., p 539.)
General guidelines for the use of FEV1 in assessing the patient’s ability to tolerate pulmonary resection are as follows: patients with an FEV1 of >2.0 L can tolerate pneumonectomy, and those with an FEV1 of >1.5 L can tolerate lobectomy. It must be emphasized that these are guidelines only. It is also important to note that the raw value is often imprecise, because normal values are reported as ‘percent predicted’ based on corrections made for age, height, and gender.
FIG. 19-8. Algorithm for preoperative evaluation of pulmonary function and reserve before resectional lung surgery. CPET = cardiopulmonary exercise test; CT = computed tomographic scan; CXR = chest radiograph; DLCO = carbon monoxide diffusion capacity; FEV1 = forced expiratory volume in 1 second; %ppo = percent predicted postoperative lung function; VO2max = maximum oxygen consumption. (Reproduced with permission from Colice GL, Shafazand S, Griffin JP, et al: Physiologic evaluation of the patient with lung cancer being considered for resectional surgery: ACCP evidence-based clinical practice guidelines (2nd edition). Chest 132(3 Suppl):161S, 2007.)
The percent predicted value for both FEV1 and DLCO correlates with the risk of development of complications postoperatively, particularly pulmonary complications. Complication rates are significantly higher among patients with percent predicted values of 50%, with the risk of complications increasing in a stepwise fashion for each 10% decline. Figure 19-9 shows the relationship between predicted postoperative DLCO and estimated operative mortality. (See Schwartz 9th ed., p 540.)
FIG. 19-9. Operative mortality after major pulmonary resection for non–small cell lung cancer (334 patients) as a function of the percent predicted postoperative carbon monoxide diffusion capacity (ppoDLCO%). Solid line is the logistic regression model; dashed lines represent the 95% confidence limits. (Adapted with permission from Wang J, et al: Diffusing capacity predicts operative mortality but not long-term survival after resection for lung cancer. J Thorac Cardiovasc Surg 117:582, 1999. Copyright © Elsevier.)
Exercise testing that yields maximum oxygen consumption (VO2max) has emerged as a valuable decision-making technique to help in evaluation of patients with abnormal FEV1 and DLCO. Table 19-7 provides a summary of the existing data regarding the relationship between VO2max and postoperative mortality risk. It is not uncommon to encounter patients with significant reductions in percent predicted FEV1 and DLCO whose history shows a functional status that is inconsistent with the pulmonary function test results. In these circumstances, and in other situations in which decision making is difficult, the VO2max should be measured. Values of 10 mL/kg per minute generally prohibit any major pulmonary resection, because the mortality associated with this level is 26%, compared with only 8.3% for VO2max levels of ≥10 mL/kg per minute; VO2max levels >15 mL/kg per minute generally indicate the patient’s ability to tolerate pneumonectomy. (See Schwartz 9th ed., pp 541-542.)
TABLE 19-7 Relation between maximum oxygen consumption (
o2max) as determined by preoperative exercise testing and perioperative mortality
28. Which lymph node stations can be assessed for metastatic disease via endoesophageal ultrasound (EUS)?
A. 2R and 2L—upper paratracheal nodes
B. 4R and 4L—lower paratracheal nodes
C. 5—aorto-pulmonary nodes
D. 6—pre-aortic nodes
Answer: B
Endoesophageal ultrasound (EUS) has recently emerged as a method of staging in NSCLC. EUS can accurately visualize mediastinal paratracheal lymph nodes (stations 4R, 7, and 4L) and other lymph node stations (stations 8 and 9). It is able to visualize primary lung lesions contiguous with or near the esophagus (see Fig. 19-1). Using FNA techniques and, more recently, core-needle biopsy, samples of lymph nodes or primary lesions can be obtained. Diagnostic yield is improved with intraoperative cytologic evaluation, which can be performed with the cytopathologist in the operating room. Limitations of EUS include the inability to visualize the anterior (pretracheal) mediastinum, and thus it does not replace mediastinoscopy for complete mediastinal nodal staging. However, it may not be necessary to perform mediastinoscopy if findings on EUS are positive for N2 nodal disease, particularly if more than one station is found to harbor metastases. (See Schwartz 9th ed., p 538, and Fig. 19-1.)
29. Surgical intervention is required in most patients infected with
A. Actinomyces israelii
B. Mycobacterium tuberculosis
C. Mycobacterium kansasii
D. M. avium-intracellulare complex
Answer: D
Rifampin and isoniazid augmented with one or more second-line drugs are most commonly used to treat NTM infections. Generally, therapy lasts approximately 18 months. The overall response is satisfactory in 70 to 80% of patients with M. kansasii infection. Surgical intervention rarely is required in those 20 to 30% who do not respond to medical therapy. In contrast, pulmonary MAC [M. avium-intracellulare complex] infections respond poorly, even to combinations of four or more drugs, and most patients eventually require surgical intervention. (See Schwartz 9th ed., p 554.)
Actinomycosis is a chronic disease usually caused by Actinomyces israelii. It is characterized by chronic suppuration, sinus formation, and discharge of purulent material containing yellow-brown sulfur granules. Approximately 15% of infections involve the thorax; organisms enter the lungs via the oral cavity (where they normally reside). Because the disease is uncommon, making the correct diagnosis can be challenging, and the clinician must first suspect the disease and then perform appropriate culture analysis under anaerobic conditions. Lung involvement can present with progressive pulmonary fibrosis in the periphery. Pleural and chest wall involvement (periostitis of the ribs) is an associated finding. Treatment consists of prolonged high-dose penicillin, which is very effective. Because of the intense fibrotic reaction surrounding affected parenchyma, surgery is seldom possible. (See Schwartz 9th ed., p 555.)
30. Which of the following is a primary indication for the use of indwelling pleural catheters to treat malignant pleural effusion?
A. Poor expansion of the lung
B. Purulent, foul-smelling pleural fluid
C. Long life expectancy
D. Positive results of D-dimer blood test
Answer: A
Before the pleural cavity is sclerosed, whether by chest tube or VATS, the lung should be nearly fully expanded. Poor expansion of the lung (because of entrapment by tumor or adhesions) generally predicts a poor result with pleurodesis and is the primary indication for placement of indwelling pleural catheters. These catheters have dramatically changed the management of end-stage cancer treatment because they substantially shorten the amount of time patients spend in the hospital during their final weeks of life. The choices for sclerosing agent include talc, bleomycin, and doxycycline. Success rates for controlling the effusion range from 60 to 90%, depending on the exact scope of the clinical study, the degree of lung expansion after the pleural fluid is drained, and the care with which the outcomes were reported. Figure 19-10 presents a decision algorithm for the management of malignant pleural effusion. (See Schwartz 9th ed., p 579.)
FIG. 19-10. Treatment decision algorithm for the management of malignant pleural effusion (MPE). CT = computed tomography; VATS = video-assisted thoracic surgery.
31. When treating trauma victims, which thoracic surgical approach is typically used?
A. Median sternotomy
B. Video-assisted thoracoscopic surgery
C. Posterolateral thoracotomy
D. Anterolateral thoracotomy
Answer: D
The anterolateral thoracotomy has traditionally been used in trauma victims. This approach allows quick entry into the chest with the patient supine. (See Schwartz 9th ed., p 523.)
32. Using the proposed changes to the lung cancer staging system, which of the following is the appropriate TNM stage for a patient with a 2-cm squamous cell cancer in the right upper lobe with positive left level 4 mediastinal lymph nodes and a right malignant pleural effusion?
A. T1a N1 M0, Stage IIa
B. T1b N2 M1a, Stage IV
C. T2a N1 M0, Stage IIa
D. T1b N2 M0, Stage IIIa
Answer: B
In 1986, an international staging system for lung cancer was developed by Mountain and applied to a database of >3000 patients from the M. D. Anderson Hospital in Houston, Texas, and the Lung Cancer Study Group. In 1997, Mountain reviewed the survival data from an additional 1524 patients beyond the original database. Taking into account the combined total of 5319 patients, he revised the staging system. These changes were subsequently adopted by the American Joint Committee on Cancer. The 1997 version of the international staging system, which is still in use, is shown in Table 19-8.
Significant variation in survival is seen within stage groupings, however (Table 19-9), which has prompted a critical evaluation of the variables that predict poor long-term survival. For example, a tumor that is ≤1.0 cm in diameter has a significantly better prognosis than tumors 2.0 to 3.0 cm in diameter. The wide range of postoperative 5-year survival rates (5 to 25%) after surgical resection of patients with N2 nodal involvement demonstrates the effect of the number and location of involved nodal stations and of the presence of extracapsular nodal extension.
To address the wide variability in survival within stages, the International Association for the Study of Lung Cancer Staging Committee was created in 1999. A database encompassing over 100,000 patients worldwide has been created and intensively examined for important determinants of survival by tumor, node, and metastasis staging. The results of this analysis, as well as recommended changes to the TNM staging system, have been recently published after vigorous analysis of multinational data. These changes were validated in 23,583 patients and shown to predict survival better than the current staging system. Proposed changes to the TNM staging are outlined in Tables 19-10 and 19-11. (See Schwartz 9th ed., p 542.)
TABLE 19-8 American Joint Committee on Cancer staging system for lung cancer
TABLE 19-9 Cumulative percentage of survival by stage after treatment for lung cancer
TABLE 19-10 Summary of proposed lung cancer staging revisions
TABLE 19-11 International Association for the Study of Lung Cancer proposed changes to the tumor, nodes, and metastasis (TNM) staging system for 2009
