Pul 11 - Lung Cancer

Question 1

How is lung cancer classified?

Answer 1

According to histological type.

1. Small cell (oat cell) lung carcinoma.
2. Non-small cell carcinoma (3):
   - Adenocarcinoma.
   - Squamous-cell carcinoma.
   - Large-cell lung cancer.

-All are related to smoking: responsible for 90% of these cancers.

Question 2

Which type of lung cancer is the most common?

Answer 2

Adenocarcinoma.

Question 3

Where in the lungs does adenocarcinoma of lungs prefer?

Answer 3

At the peripheries of the lungs, often found in pre-existing parenchymal scars.

Question 4

What is the most common type of lung cancer in non-smoking females?

Answer 4

Adenocarcinoma.

Question 5

Which gene mutation is related to adenocarcinoma of the lungs and what tumor marker does it release?

Answer 5

It is related to K-ras oncogene. It is CEA-positive.

Question 6

What is bronchioalveolar carcinoma?

Answer 6

A subtype of adenocarcinoma, it is associated with smoking (many past books say it wasn’t). The tumor cells line the alveolar walls.

Question 7

What is the preferred location of brochioalveolar carcinoma?

Answer 7

Periphery of lung.

Question 8

What can bronchioalveolar carcinoma initially present as?

Answer 8

As pneumonia (infiltrate on CXR).

Question 9

What is the preferred location of large cell carcinoma of lung?

Answer 9

Periphery of lung.

Question 10

What is the histology of Large Cell carcinoma of lung?

Answer 10

• Anaplastic cells.
• Undifferentiated cells.
• Giants cells in various pleomorphisms.
• Very poor prognosis as it responds poorly to chemo.

Question 11

Where is the preferred location of squamous cell carcinoma of the lung?

Answer 11

Centrally located in the lungs. Often present as a hylar mass of the bronchus, or cavitated lesion on CXR.

Question 12

What is the histological finding of squamous cell carcinoma?

Answer 12

• Keratin pearls.

- Can secrete certain hormones (PTH-related protein).

Question 13

What is the most common hormone secreted by squamous cell carcinoma of the lungs?

Answer 13

PTH-related protein causing hypercalcemia.

Question 14

Why is it called small cell carcinoma of the lung?

Answer 14

Because of the nucleus to cytoplasm ratio is very high.

Question 15

What is the preferred location of small cell carcinoma of the lungs?

Answer 15

Centrally in the lung.

Question 16

What hormones can small cell carcinoma of the lung secrete?

Answer 16

• ACTH.

- ADH.

Question 17

What are the histological finding of small cell carcinoma?

Answer 17

• Undifferentiated and aggresive.

- Dark blue cells called “Kulchitsky cells” or enterochromaffin (EC) cells: they release serotonin.

Question 18

What is small cell carcinoma associated with?

Answer 18

Lambert-Eaton myasthenic syndrome (LMES): autoimmune disease, which affects the neuromuscular junction calcium channels. In this pathology, the weakness improves with use. Also associated with NYC oncogenes.

Question 19

What are symptoms of carcinoid syndrome?

Answer 19

[Bitch, its FDR]

1. Bronchospasm and wheezing
2. Flushing.
3. Diarrhea.
4. Right-sided heart lesions.
   - valvular lesions and heart murmur.

Question 20

What are the two most common location of carcinoid tumor and why do they have to be there to cause carcinoid syndrome?

Answer 20

1. Lungs.
2. GI tract (most common tumor of the appendix).
   - They have to be in the lungs or metastatic disease from GI tract to liver because the liver inactivates the serotonin, that causes a lot of these symptoms. Or from the lungs that directly puts those substances into the venous.

Question 21

Where does the Pancoast tumor occur and what syndrome does it cause?

Answer 21

Occurs at the apex of the lung. It causes Horner syndrome.

Question 22

What are the symptoms of Horner syndrome?

Answer 22

1. Ptosis.
2. Miosis.
3. Anhidrosis.
   (Can also compress the recurrent laryngeal nerve, causing hoarse voice).

Question 23

What region of the lungs does mesothelioma occur?

Answer 23

Pleura or outer lining of the lungs.

• Can also rise in the peritonium, pericardium, tunica vaginalis (sac that surrounds testes).
• There is no association of smoking and mesothelioma.

Question 24

What histological findings do we see in mesothelioma?

Answer 24

Psommoma bodies (round collections of calcium).

Question 25

What are the most common sites of lung metastasis?

Answer 25

1. Brain.
2. Bone.
3. Liver.
4. Adrenal.

Question 26

What element increases the risk of lung cancer?

Answer 26

• Radon (Rn 86).

- Found in basements and coal mines.

Question 27

A patient develops bronchogenic lung cancer but has never smoked. He is a coal miner. What is the cause of the cancer?

Answer 27

Radon gas. There is no asbestos in coal mines.

Question 28

What complications can arise from lung cancer?

Answer 28

1. Superior vena cava syndrome.
2. Horner syndrome.
3. Paraneoplastic syndromes:
   - Squamous cell can make PTH-related hormone: Hypercalcemia
   - Small cell can make ACTH: Cushing syndrome
   - Small cell can make ADH: SIADH and hyponatremia.
   - Small cell can make autoantibodies against calcium channels: Lambert-Eaton syndrome and weakness.
4. Invasion into the recurrent laryngeal nerve, causing hoarseness.
5. Pleural effusion.
6. Esophageal invasion causing dysphagia.
7. Laryngeal invasion.

Question 29

RFF: Lung cancer associated with SIADH.

Answer 29

Small cell lung cancer.

Question 30

RFF: Tumor associated with Horner sydrome.

Answer 30

Pancoast tumor.

Question 31

What some symptoms of lung cancer?

Answer 31

1. Cough.
2. Hemoptysis.
3. Weight loss.
4. Night sweats.
5. Airway obstruction.
6. Paraneoplastic syndromes.