Tumors of the chest wall, mediastinum and lungs

Question 1

General info on chest wall tumors

Answer 1

Most tumors of the chest wall are malignant and most are metastatic by direct extension such as lung and breast or hematogenously spread such as sarcomas. Primary chest wall tumors are rare – less than 1% of all primary tumors
In patients who undergo chest wall resection, only about 25% of cases were for primary chest wall tumors

Question 2

What is the most common area to have a tumor on the chest?

Answer 2

rib cage is far more common than the sternum, scapulae or clavicles

Question 3

what are more common, benign or malignant chest wall tumors?

Answer 3

malignant

Question 4

Soft tissue tumors:

Answer 4

include benign lesions such as lipomas, fibromas and hemangiomas or malignant lesions such as desmoid tumors (considered a variant of fibrosarcoma), fibrosarcoma, liposarcoma and rhabdomyosarcoma

Question 5

Bone/cartilaginous tumors:

Answer 5

can be benign such as osteochondroma, chondroma and fibrous dysplasia while the malignant lesions are osteosarcomas, chondrosarcomas, Ewing’s sarcoma and plasmacytoma (75% of patients will have/or develop multiple myeloma)

Question 6

Tx of benign lesions:

Answer 6

surgical resection

Question 7

Tx of malignant lesions:

Answer 7

involves a combination of chemotherapy, radiation therapy and surgery

Question 8

Mediastinum:

Answer 8

Definition – The thoracic space between the two pleural cavities
Extends from the thoracic inlet to the diaphragm
Many arbitrary divisions of the mediastinum based upon the anatomy
Most commonly – anterior, middle and posterior

Question 9

Anterior Mediastinal Structures:

Answer 9

Thymus gland
Internal mammary vessels and lymph nodes
Displaced parathyroid glands (rare)
Ectopic thyroid tissue (rare)

Question 10

Middle Mediastinal structures:

Answer 10

Pericardium, heart and great vessels
Trachea and mainstem bronchi
Esophagus
Vagus and Phrenic nerves
Thoracic duct

Question 11

Posterior Mediastinal Structures:

Answer 11

Intercostal arteries and veins
Spinal ganglions, sympathetic trunk and intercostal nerves
(Descending aorta)

Question 12

• 4 T’s (anterior mediastinal Masses):

Answer 12

• Thymoma
• Thyroid (substernal goiter)
• Teratoma (and other germ cell tumors)
• Terrible lymphoma
• others, not T’s (cystic hygroma, parathyroid, paraganglioma)

Question 13

Thymus:

Answer 13

Essential for the development of cellular immunity
Programmed cellular immunity occurs before birth as there are no known clinical problems associated with thymectomy in neonates

Question 14

DiGeorge Syndrome –

Answer 14

genetic disorder which results in thymic aplasia and subsequent profound immunodeficiency disease

Question 15

Thymomas are…

Answer 15

tumors of the *epithelial cells of the thymus - *NOT the lymphocytes

Question 16

Thymomas:

Answer 16

Are more common in adults
30 % are asymptomatic, 40 % have local symptoms and 30 % have distant symptoms (paraneoplastic syndromes)
About 45 % of patients with a thymoma have myasthenia gravis and 10 % of the patients with myasthenia gravis have a thymoma

Question 17

Thymoma labs and intervention:

Answer 17

Accurate staging is with CT, MRI and PET
Surgical intervention whenever possible
If the tumor is unresectable, adjuvant treatment with chemotherapy and radiation therapy should be considered
Staging is with the TNM classification or the Masaoka classification

Question 18

TNM=

Answer 18

T= Tumor, N= lymph node involvement, M= medistatic

Question 19

Thymoma Tx:

Answer 19

Complete resection is the gold standard
10 year survival rates are 90 %, 70 %, 55 % and 35 % for stages I – IV
If the tumor cannot be completely resected, there is some evidence that surgical debulking may be beneficial
Remember that myasthenia gravis is a life threatening disease that complicates surgical intervention

Question 20

Middle Mediastinal Masses:

Answer 20

Adenopathy (sarcoid, lymphoma, infectious)
Aneurysms and Dissections
Pericardial cysts
Tracheal tumors
Esophageal tumors

Question 21

Posterior Mediastinal Masses:

Answer 21

Bone tumors (rare)
Neurogenic tumors
Schwannoma (benign, adult). Multiple schwannomas can be associated with neurofibromatosis or Von Recklinghausen’s disease (The Elephant Man). Comprised of Schwann cells.
Neurofibromas (benign, adult). Comprised of Schwann cells, fibroblasts, mast cells, and endothelial cells.
Neuroblastoma (malignant, childhood). Derived from neural crest cells of the sympathetic nervous system. Most commonly found in the adrenals

Question 22

Tx of Mediastinal Masses:

Answer 22

Most mediastinal masses should be surgically removed both for diagnosis and treatment
Exceptions are pericardial cysts and clearly benign nerve sheath tumors
Surgery plays no role (other than biopsy) for sarcoid, infections, or lymphoma

Question 23

Preinvasive lesions

Answer 23

Squamous cell carcinoma in situ and atypical adenomatous hyperplasia

Question 24

Most common benign lung tumor?

Answer 24

Hamartoma

Question 25

Hamartoma -

Answer 25

-benign
- Composed of varying proportions of cartilage, fat, connective tissue and smooth muscle.
Appear as smooth bordered tumors more commonly in men than women
Treatment is surgical resection if indicated

Question 26

Carcinoid tumors:

Answer 26

previously classified as benign lesions with varying degrees of malignant potential
They are frequently discovered as round, smooth bordered lung masses though they may also be found within the bronchial lumen
They are now considered low grade neuroendocrine carcinomas

Question 27

Tx of Carcinoid rumors?

Answer 27

should be resected whenever possible due to the possibility of metastatic disease

Question 28

Typical carcinoid:

Answer 28

bland histology with low metastatic potential

Question 29

Atypical Carcinoid:

Answer 29

more mitotic active with higher metastatic potential

Question 30

leading cause of cancer death in the us?

Answer 30

Lung

Question 31

Risk factors for lung cancer:

Answer 31

Smokers
Second hand smoke – exposure to prolonged second hand smoke will increase the risk of lung cancer by 20 – 30 percent
Radon – it is estimated that radon causes 10 percent of all lung cancers
Asbestos
Air pollution
Exposure to certain chemicals such as uranium, beryllium, gasoline and diesel exhaust
Arsenic in the drinking water
Genetics
Prior radiation to the breast or lungs

Question 32

Lung Cancer:

Answer 32

Classification is based upon histology - SMALL CELL and NON-SMALL CELL
The non-small cell type is further divided into:
Adenocarcinoma
Squamous cell carcinoma
Large cell undifferentiated carcinoma
Large cell neuroendocrine carcinoma
Well differentiated neuroendocrine carcinoma (carcinoid)

Question 33

Small Cell

Answer 33

Comprises about 20 % of all lung cancers
Is correctly staged using the TNM classification but clinically is most often staged as “limited” stage and “extensive” stage.
Very rarely is this tumor treated with surgery alone as most patients will present with inoperable tumors
Combination chemoradiotherapy is used for limited stage and chemotherapy alone for extensinve stage
Account for 80 % of all lung cancers
Adeonocarcinoma and Squamous Cell carcinoma comprise the vast majority of non-small cell lung tumors

Question 34

Tx of Non-small cell carcinoma

Answer 34

surgery for localized disease and radiation therapy or chemotherapy for more advanced disease

Question 35

LUNG CANCER STAGE AT PRESENTATION

Answer 35

It is estimated that only 35 % of all patients with lung cancer will present with a surgically amenable stage of tumor (stage I or II)
Of those 35 %, about half will not be surgical candidates due to comorbid conditions.
The overall 5 year survival for newly diagnosed lung cancer is about 17%

Question 36

Clinical S/S of lung cancer?

Answer 36

Cough 
Dyspnea 
Hemoptysis
Hoarseness 
Chest Pain
Neurologic
Weight Loss
Anorexia
Fatigue

Question 37

PARANEOPLASTIC SYNDROMES

Answer 37

Lung cancer is the most common tumor associated with paraneoplastic syndromes
Paraneoplastic signs and symptoms may be present before the lung cancer is discovered
Effective treatment of the tumor will result in resolution of the syndrome
Can occur with any cell type though certain syndromes are more closely associated with certain cell types

Question 38

Paraneoplastic Metabolic

Syndrome:

Answer 38

Hypercalcemia due to production of parathyroid hormone like proteins (squamous cell). Hyponatremia due to SIADH (small cell). Cushing’s syndrome due to ACTH (small cell and carcinoid)

Question 39

Paraneoplastic Skeletal

syndrome:

Answer 39

Clubbing and Hypertrophic Pulmonary Osteoarthropathy (VEGF). More common with adenocarcinoma.

Question 40

Paraneoplastic neurologic syndrome:

Answer 40

Enchephalomyelitis and sensory neuropathies (immune mediated). More common with small cell

Question 41

Paraneoplastic muscular syndrome

Answer 41

Lambert-Eaton syndrome presents similar to myasthenia gravis and is due to antibodies directed at axonal calcium channels that inhibit the release of acetylcholine. More common with small cell

Question 42

paraneoplastic hematologic syndrome

Answer 42

thrombocytosis and a hypercoagulable state leading to both venous and arterial thrombosis. Mechanism is unknown. More common with adenocarcinomas and small cell. AKA Trousseau’s Syndrome

Question 43

Lung Cancer Staging:

Answer 43

Chest Xray is the most common first step
CT of the chest with intravenous contrast is performed for any suspicious chest xray
If the CT suggests that the lesion in question may be a malignancy, then a PET scan is ordered
The PET scan will theoretically stage the patient and will provide information about the most suitable biopsy site

Question 44

Most accurate way for staging lung cancer?

Answer 44

biopsy

-necessary for tx and prognosis

Question 45

Tx of non-small cell lung cancer:

Answer 45

After proper clinical staging, decision about whether the patient is a surgical candidate
Work up for determination of a surgical candidate would include an accurate assessment of cardiac (EKG, Echo, Stress Study) and pulmonary function (ABG, PFTs) and in some cases exercise testing for measurement of oxygen consumption.

Question 46

Tx of non-small cell lung cancer cont.”

Answer 46

If the patient is deemed a surgical candidate and consents, then a biopsy is not necessary prior to surgery
If the patient is not a surgical candidate then a biopsy is usually performed to determine the exact cell type which influences the type of chemotherapy/radiotherapy given.

Question 47

Tx of non-small cell lung cancer based on staging:

Answer 47

Clinical Stage I – Surgery is preferred (Radiation is considered alternative)
Clinical Stage II – Surgery is preferred (Radiation and Chemotheray is considered alternative)
Clinical Stage III – Radiation and Chemotherapy
Clinical Stage IV – Chemotherapy alone

Question 48

Surgery for localized lunger:

Answer 48

For stage I – Options include removal of a portion of the lung (wedge), a lobe of the lung (lobectomy) or the entire lung (pneumonectomy). Survival is 60%
For Stage II – Options include removal of a lobe of the lung or the entire lung. Survival is 40%

Question 49

Radiation Therapy for lung cancer based on stages:

Answer 49

Stage I – Traditional radiation therapy (therapy 5 days a week for 6 weeks) is about half as effective as surgery. Survival is 30%.
Stage II – Traditional radiation therapy has about a 20% survival
Stage III – Survival declines to less than 20%
Stage IV – Used only for palliation such as bone pain

Question 50

Chemotherapy for lung cancer:

Answer 50

Chemotherapy has little role to play in early stages of lung cancer
It is usually reserved for stages III and IV which have poor survival rates
Targeted therapy (drug testing, gene mutations) holds promise but it is still not widely accepted and is not “mainstream”. It is expensive, has risks and the role is still unknown.

Question 51

Tx of Small cell lung cancer?

Answer 51

The majority (95%) of patients who develop small cell lung cancer present with advanced stages of tumor
Surgery is usually not possible except in rare cases where the tumor is incidentally found
Stage for stage, survival is similar to non-small cell but overall worse because of the advanced stage at presentation
Treatment is chemotherapy and radiation

Question 52

Prognosis and and screening:

Answer 52

Clearly, prognosis is related to the stage at which the lung cancer is discovered.
Screening for lung cancer may find “incidental” tumors at an early stage
The initial studies used to screen large populations of patients used chest xray alone
A simple chest xray is not sensitive enough to detect early stages of lung cancer

Question 53

National lung screening trial:

Answer 53

Found a 20.0% reduction in lung cancer related deaths in the CT group compared to the chest xray group
Found a 6.7% reduction in the rate of death from any cause in the CT group (found more aneurysms, kidney tumors, pneumonias, etc.)
96.4% and 94.5% of the positive tests in the CT and chest xray groups were “false”

Question 54

Lung cancer screening:

Answer 54

Some estimate that 40 million people will be eligible for screening.
20% of all CT scans are “abnormal” (but only a few are cancer) and require serial scans to document growth or stability of the abnormality in question

Question 55

Stereotactic Body Frame Radiotherapy (SBRT):

Answer 55

new radiation technique that is very promising
It utilizes many different xray beams to specifically target the tumor and not the rest of the body
It is very promising in treating early stage tumors

Question 56

SBRT info

Answer 56

Radiation therapy given in 3 – 5 doses instead of the usual 30
Results are still being compiled
There is an ongoing randomized trial that is comparing SBRT to Surgery in early stage lung cancer in patients who are high risk for traditional surgery

Question 57

Radiofrequency ablation

Answer 57

This technique uses a multipronged needle to pass energy into the lung.
The needle heats the surrounding tumor (and to some extent the normal lung) to such a high temperature that the cells just die, leaving a small cavity where the tumor was
Some have been using cryotherapy as well

Question 58

Radiofrequency ablation cont.

Answer 58

Is usually done under general anesthesia in the CT scanner
Takes an hour or two
That is all you get!!!!
Can be repeated if necessary
Results are still being compiled but seem inferior to surgery, radiation, or SBRT
Trials are ongoing

Question 59

lung cancer prevention:

Answer 59

Nothing has been shown to convincingly and consistently prevent lung cancer
Exercise is reported to lower the risk of many different cancers but the data is very weak
Diets high in fruits and vegetables may also lower the risk of lung cancer but the data is very weak and beta-carotene has been associated with a higher risk of lung cancer

Question 60

Lung cancer summary:

Answer 60

Smoking cessation and abstinence are key
Lung cancer screening is effective but who and who pays???
Surgery is still considered treatment of choice in early stage lung cancer
Newer alternatives to surgery are emerging, particularly SBRT
Prompt referral to a surgeon is key to treatment