STEPUP Diseases of the Pulmonary System: Lung Neoplasms

Question 1

What are pathologic types of lung cancer divided into?

Answer 1

Two subgroups:

1) Small cell lung cancer (SCLC) - 25% of lung cancers
2) Nonsmall cell lung cancer (NSCLC) - 75% of lung cancers; includes squamous cell carcinoma, adenocarcinoma, large cell carcinoma, and bronchoalveolar cell carcinoma

Question 2

What are risk factors for lung cancer?

Answer 2

1) Cigarette smoking - accounts for > 85% of cases
2) Second-hand smoke
3) Asbestos
4) Radon
5) COPD - an independent risk factor after smoking is taken into account

Question 3

What relationship is there between cigarette smoking and lung cancer? Which type of lung cancer has the lowest association with smoking?

Answer 3

1) There is a linear relationship between pack-years of smoking and risk of lung cancer
2) Adenocarcinoma has the lowest association with smoking of all lung cancers

Question 4

Where is asbestos common? How do smoking and asbestos work together to increase the risk of lung cancer?

Answer 4

1) Common in shipbuilding and construction industry, car mechanics, painting
2) Smoking and asbestos in combination synergistically increase the risk of lung cancer

Question 5

Where is radon found in high levels?

Answer 5

Basements

Question 6

How is non small cell lung cancer staged? How is small cell lung cancer staged?

Answer 6

1) NSCLC is staged via the primary TNM system
2) SCLC is staged differently (though some recommend TNM staging still be used):
a) Limited - confined to chest plus supraclavicular nodes, but not cervical or axillary nodes
b) Extensive - outside of chest and supraclavicular nodes

Question 7

Why is it important to differentiate between small cell and non small cell lung cancer in diagnosis? How is this done?

Answer 7

1) In the diagnosis of lung cancer, it is crucial to differentiate between small cell (25%) and nonsmall cell (75%) types because the treatment approach is completely different
2) A tissue diagnosis is necessary to make this differentiation

Question 8

What are local manifestations of lung cancer?

Answer 8

1) Airway involvement can lead to cough, hemoptysis, obstruction, wheezing, dyspnea
2) Recurrent pneumonia (postobstructive pneumonia)
Squamous cell carcinoma is most commonly associated with these symptoms

Question 9

What are constitutional symptoms found in lung cancer? What are they indicative of?

Answer 9

1) Anorexia, weight loss, weakness

2) Usually indicative of advanced disease

Question 10

What are some examples of local invasion of lung cancer?

Answer 10

1) Superior vena cava (SVC) syndrome (5% of patients)
2) Phrenic nerve palsy (1% of patients)
3) Recurrent laryngeal nerve palsy (3% of patients)
4) Horner syndrome
5) Pancoast tumor
6) Malignant pleural effusion (10% to 15% of patients)

Question 11

What is SVC syndrome caused by? With which cancer does it most commonly occur? What are some findings on physical exam?

Answer 11

1) Caused by obstruction of SVC by a mediastinal tumor
2) Most commonly occurs with SCLC
3) Findings: facial fullness; facial and arm edema; dilated veins over anterior chest, arms, and face; jugular venous distention (JVD)

Question 12

How does phrenic nerve palsy occur? What does it result in?

Answer 12

1) Destruction of the phrenic nerve by tumor; phrenic nerve courses through the mediastinum to innervate the diaphragm
2) Results in hemidiaphragmatic paralysis

Question 13

What does a recurrent laryngeal nerve palsy cause?

Answer 13

Hoarseness

Question 14

Tumor invasion where causes horner syndrome? What are the symptoms?

Answer 14

1) Due to invasion of cervical sympathetic chain by an apical tumor
2) Symptoms: unilateral facial anhidrosis (no sweating), ptosis, and miosis

Question 15

Where does a pancoast tumor occur? What type of cancers generally cause it? What are the symptoms? How often is a pancoast tumor associated with horner syndrome?

Answer 15

1) Superior sulcus tumor - an apical tumor involving C8 and T1-T2 nerve roots, causing shoulder pain radiating down the arm
2) Usually squamous cell cancers
3) Symptoms: pain; upper extremity weakness due to brachial plexus invasion
4) Associated with Horner syndrome 60% of the time

Question 16

What is unfortunate about the signs and symptoms of lung cancer?

Answer 16

Unfortunately, signs and symptoms are generally nonspecific for lung cancer, and by the time they are present, disease is usually widespread

Question 17

What is the prognosis when malignant pleural effusion is seen in lung cancer?

Answer 17

Prognosis is very poor - equivalent to distant metastases

Question 18

What are the most common sites of metastatic disease in lung cancer?

Answer 18

Brain, bone, adrenal glands, and liver

Question 19

What are the different paraneoplastic syndromes that can occur in lung cancer?

Answer 19

1) SIADH
2) Ectopic ACTH secretion
3) PTH-like hormone secretion
4) Hypertrophic pulmonary osteoarthropathy
5) Eaton-Lambert syndrome
6) Digital clubbing

Question 20

SIADH is usually seen with which lung cancer? Ectopic ACTH secretion? PTH-like hormone secretion? Hypertrophic pulmonary osteoarthropathy?

Answer 20

1) Small cell carcinoma (10% of SCLC patients)
2) Small cell carcinoma
3) Squamous cell carcinoma
4) Adenocarcinoma and squamous cell carcinoma - severe long-bone pain may be present

Question 21

In which lung cancer is Eaton-Lambert syndrome more common. What is the clinical picture like?

Answer 21

1) Most common in SCLC
2) Clinical picture is similar to that of myasthenia gravis, with proximal muscle weakness/fatigability, diminished deep tendon reflexes, paresthesias (more common in lower extremities)

Question 22

What is digital clubbing?

Answer 22

Loss of normal angle between the fingernail and nail bed due to thickening of subungual soft tissue

Question 23

What is the prognosis of SCLC for limited disease? For extensive disease?

Answer 23

1) For limited disease, 5-year survival is 10% to 13% (median survival ranges from 15 to 20 months)
2) For extensive disease, 5-year survival rate is 1% to 2% (median survival is 8 to 13 months)

Question 24

For lung cancer, what tests should you obtain?

Answer 24

1) CXR
2) CT scan
3) Tissue biopsy to confirm diagnosis
4) Determine histologic type (SCLC or NSCLC)

Question 25

What is the most important radiologic study for diagnosis of lung cancer? What should you not use this test for in lung cancer? What should it demonstrate in nearly all patients? Using this test, how can you determine if a lesion is almost always benign?

Answer 25

1) A CXR
2) Not used as a screening test
3) Abnormal findings in nearly all patients with lung cancer
4) Stability of an abnormality over a 2-year period is almost always associated with a benign lesion

Question 26

What imaging study is very useful for staging of lung cancer? What can it demonstrate? What is it very accurate in revealing?

Answer 26

1) CT scan of the chest with IV contrast
2) Extent of local and distant metastasis
3) Lymphadenopathy in mediastinum

Question 27

What test is decent for diagnosing central lung tumors (in 80%), but not peripheral lesions? What is a downside of this test?

Answer 27

1) Cytologic examination of sputum

2) Provides highly variable results; if negative and clinical suspicion is high, further tests are indicated

Question 28

What test is very useful for diagnosing central visualized tumors, but not peripheral lesions and why? What do larger and more central lesions indicate for the test yield? In terms of percentage, how diagnostic is a bronchoscopy for visible lesions?

Answer 28

1) A fiberoptic bronchoscope because it can only be inserted as far as secondary branches of bronchial tree
2) The larger and more central the lesion, the higher the diagnostic yield
3) For visible lesions, the bronchoscopy is diagnostic in >90% of cases

Question 29

What does a whole body positron emission tomography (PET) help with in lung cancer?

Answer 29

Provides additional information that primary tumor is malignant, detects lymph node and intrathoracic and distant metastases

Question 30

Is a transthoracic needle biopsy (under fluoroscopic or CT guidance) accurate and what is it useful for? When is it to be used?

Answer 30

1) Needle biopsy of suspicious pulmonary masses is highly accurate, and is useful for diagnosing peripheral lesions as well
2) Needle biopsy is invasive and must be used only in selected patients. This is a better biopsy method for peripheral lesions, whereas central, peribronchial lesions should be biopsied using bronchoscopy

Question 31

What does mediastinoscopy allow for visualization of? Which patients with lung cancer does it identify?

Answer 31

1) Allows direct visualization of the superior mediastinum

2) Identifies patients with advanced disease who would not benefit from surgical resection

Question 32

What may CXR show related to lung cancer beside any masses? What should you do with this finding? Regardless of the findings on CXR or CT scan, what is required for definitive diagnosis of lung cancer?

Answer 32

1) A pleural effusion, which should be tapped
2) The fluid should be examined for malignant cells
3) Pathologic confirmation

Question 33

What test should you always do for intrathoracic lymphadenopathy?

Answer 33

Always perform a biopsy for intrathoracic lymphadenopathy (specificity for metastasis is 60%)

Question 34

What is the prognosis for lung cancer? What is the overall 5-year survival for lung cancer patients? What percentage of patients with SCLC have extensive disease at the time of presentation and when do these patients die?

Answer 34

1) The prognosis for lung cancer is grim
2) Overall 5-year survival for lung cancer patients is 14%
3) 85% of patients with SCLC have extensive disease at the time of presentation
4) Almost all of die within 2 years of presentation

Question 35

What is the best treatment for NSCLC? What must be done prior to this treatment? Which patients are not candidates for this treatment? Can recurrence occur after this treatment? What treatment is an important adjunct to surgery? Is chemotherapy beneficial?

Answer 35

1) Surgery
2) A definitive pathologic diagnosis must be made prior to surgery
3) Patients with metastatic disease outside the chest are not candidates for surgery
4) Recurrence may occur even after complete resection
5) Radiation therapy
6) Chemotherapy is of uncertain benefit. Some studies show a modest increase in survival. More trials are underway

Question 36

What is the treatment for limited disease SCLC? What is the treatment for extensive disease SCLC? If a patient responds to initial chemotherapy for extensive disease SCLC, what should be done next and why? Why does surgery have a limited role in SCLC?

Answer 36

1) For limited disease, combination of chemotherapy and radiation therapy is used initially
2) For extensive disease, chemotherapy is used alone as initial treatment
3) If patient responds to initial chemotherapy for extensive disease, prophylactic radiation decreases incidence of brain metastases and prolongs survival
4) These tumors are usually nonresectable

Question 37

Are most asymptomatic masses lung cancer?

Answer 37

No, most are benign

Question 38

What is a solitary pulmonary nodule? What is the main question to ask when a solitary pulmonary nodule is found?

Answer 38

A single, well-circumscribed nodule usually discovered incidentally with no associated mediastinal or hilar lymph node involvement
2) Whether the lesion is malignant and requires biopsy or resection

Question 39

Although a solitary pulmonary nodule has a wide differential diagnosis (e.g., infectious granuloma, bronchogenic carcinoma, hamartoma, bronchial adenoma), what must one investigate the possibility of and why?

Answer 39

Malignancy because resection can lead to a cure with early detection

Question 40

What features favor benign versus malignant nodules?

Answer 40

1) Age - the older the patient, the more likely it is malignant - over 50% chance of malignancy if patient is over 50
2) Smoking - if history of smoking, more likely to be malignant
3) Size of nodule - the larger the nodule, the more likely it is malignant. Small is <1cm, large >2cm
4) Borders - malignant nodules have more irregular borders. Benign lesions have smooth-discrete borders
5) Calcification - eccentric asymmetric calcification suggests malignancy. Dense, central calcification suggests benign lesion
6) Change is size - enlarging nodule suggests malignancy

Question 41

What types of lung cancers are considered to be non small cell lung cancer? What is the incidence of each? Where are they located?

Answer 41

1) Squamous cell carcinoma, adenocarcinoma, and large cell carcinoma
2) Respectively, 30% of all lung cancers, 35% of all lung cancers - most common type, and 5%-10% of all lung cancers
3) Respectively, usually center, often peripheral, and usually peripheral

Question 42

For lung cancer, what are special features of squamous cell carcinoma? adenocarcinoma? large cell carcinoma?

Answer 42

1) Cavitation on CXR
2) a) Pleural involvement in 20% of cases
b) Less closely associated with smoking than other types
c) Can be associated with pulmonary scars/fibrosis
3) None

Question 43

What is the incidence of SCLC? Where is it usually located? What are special features of it?

Answer 43

1) 20%-25% of all lung cancers
2) Central
3) a) Tend to narrow bronchi by extrinsic compression
b) Widespread metastases are common. 50%-75% of patients have metastases outside the chest at the time of presentation

Question 44

Depending on the factors that describe a solitary lung nodule, how should you designate the nodule in terms of probability of being malignant? What tests would you do for each classification?

Answer 44

1) Low-probability nodules - serial CT scan
2) Intermediate-probability nodule 1 cm or larger - PET scan. If PET positive, biopsy
3) High-probability nodule - biopsy (transbronchial, transthoracic, or video-assisted thoracoscopic surgery) followed by lobectomy if appropriate

Question 45

What should be done when a solitary lung nodule is found? What will the test help determine?

Answer 45

1) Previous CXR is very helpful: Every effort should be made to find a previous CXR for comparison
2) If the lesion is stable for more than 2 years, it is likely benign
3) Malignant lesions grow relatively rapidly (growth is usually evident within months). However, growth over a period of days is usually nonmalignant (often infectious/inflammatory)

Question 46

What are factors that favor a benign diagnosis of solitary pulmonary nodule?

Answer 46

1) Age < 50yrs
2) Nonsmoker
3) Size of nodule <2cm
4) No growth over 2-yr period
5) Nodule circular and regular shaped
6) Central laminated calcification

Question 47

What are factors that favor a malignant diagnosis of solitary pulmonary nodule?

Answer 47

1) Age > 50yrs
2) Smoker or previous smoker
3) Size of nodule >3cm
4) Steady growth over serial radiographs
5) Nodule grossly irregular or speculated margin
6) Stippled or eccentric pattern of calcification

Question 48

What is the most common cause of mediastinal mass in older patients?

Answer 48

Metastatic cancer (especially from lung cancer)

Question 49

What is the most common cause of anterior mediastinal mass? Middle mediastinal mass? Posterior mediastinal mass?

Answer 49

1) Anterior mediastinum: “Four T’s” - thyroid, teratogenic tumors, thymoma, terrible lymphoma
2) Middle mediastinum: Lung cancer, lymphoma, aneurysms, cysts, Morgagni hernia
3) Posterior mediastinum: neurogenic tumors, esophageal masses, enteric cysts, aneurysms, Bochdalek hernia

Question 50

What are clinical features of mediastinal masses?

Answer 50

1) Usually asymptomatic
2) When symptoms are present, they are due to compression or invasion of adjacent structures
3) Cough (compression of trachea or bronchi), sometimes hemoptysis
4) Chest pain, dyspnea
5) Postobstructive pneumonia
6) Dysphagia (compression of esophagus)
7) SVC syndrome
8) Compression of nerves
a) Hoarseness (recurrent laryngeal nerve)
b) Horner syndrome (sympathetic ganglia)
c) Diaphragm paralysis (phrenic nerve)

Question 51

What is the test of choice to diagnose a mediastinal mass? How are they usually discovered?

Answer 51

1) Chest CT is test of choice

2) Usually discovered incidentally on a CXR performed for another reason

Question 52

When is observation appropriate for a mediastinal mass?

Answer 52

If CT scan suggests a benign mass and the patient is asymptomatic