Respiratory Pathology Part 4 - Witrak

Question 1

What is a unilateral hilar mass until proven otherwise?

Answer 1

Tumor => Lung cancer

Question 2

What type of lung cancer loves to cavitate?

Answer 2

squamous carcinoma

tumor becomes necrotic in the middle

Question 3

What is the common clinical presentation of lung cancer?

Answer 3

• typically age >40 years in a long term smoker.
• cough, hemoptysis, chest pain, dyspnea, hoarseness.
• chest imaging (CXR, CT scan):
  
  • mass lesion (location tendencies):
    
    • central/bronchogenic: squamous, small cell
    • peripheral: adenocarcinoma
    • atelectasis or pneumonitis: from bronchial
      obstruction.
  • hilar/mediastinal adenopathy
  • pleural/pericardial effusions.
  • chest wall invasion
    
    • in apex: Pancoast tumor with possible
      Horner’s syndrome.
  • elevated diaphragm: phrenic nerve
    paralysis.
  • superior vena cava syndrome = SVC
    compression by upper mediastinal adenopathy.

Question 4

What should you be thinking about when a smoker presents with hoarseness of the voice?

Answer 4

Think not only recurrent laryngeal nerve paralysis from mediastinal metastases: but also possible laryngeal cancer!

Question 5

What type of cancer may mimic pneumonia and is only found after failure to respond to antibiotics?

Answer 5

Bronchioloalveolar Cancer

(lepidic adenocarcinoma)

Question 6

Where do extrathoracic metastases most commonly present in lung cancer?

Answer 6

• liver
• bone: pathologic fracture may be first symptom of lung cancer
• adrenals
• brain: seizure or focal neurologic deficit may be first symptom of lung cancer

Question 7

What is a paraneoplastic syndrome?

Answer 7

tumor associated: hormone-like compounds
or stimulation of humoral factors producing
symptoms remote from tumor
(Symptoms may precede tumor diagnosis)

Question 8

What paraneoplastic syndromes are common in lung cancer?

Answer 8

-Hypercalcemia can be due to bone metastases or tumor production of PTHrP or calcitriol (Vitamin D): esp. squamous Ca.
-Small cell carcinoma:
- syndrome of inappropriate ADH (SIADH)
with hyponatremia.
- Cushing’s syndrome due to ACTH production.
- neurologic syndromes due to autoantibodies:
- Lambert-Eaton myasthenic syndrome.
- Cerebellar ataxia.
- carcinoid syndrome: diarrhea, flushing, cyanosis

Question 9

What are the systemic effects of lung cancer?

Answer 9

• Heme: anemia, leukocytosis, thrombocytosis, hypercoagulability.
• Musculoskeletal: clubbing and hypertrophic osteoarthropathy, inflammatory myopathy (myositis).

Question 10

What are the overall survival rates of lung cancer?

Answer 10

• non-small cell Ca: 15%

- small cell Ca: 5%

Question 11

What type of lung cancer has the best survival rates?

Answer 11

Carcinoid tumors: 1-5% of all lung tumors

***10 year survival is 87% (type John Wayne had :)

Question 12

What is the typical treatment for lung cancer?

Answer 12

• surgery for Stages I, II
• minority of patients are resectable.
• otherwise combination of chemo Rx, radiation Rx, and newer targeted therapy:EGFR inhibitors in adenocarcinoma.

Question 13

What is a non-epithelial primary lung tumor?

Answer 13

mixtures of mesenchymal and hematopoietic types: benign and malignant.
(commonest benign tumor = “hamartoma”)

Question 14

How common are metastic tumors to the lungs?

Answer 14

Commonest site of metastatic neoplasms: carcinomas, sarcomas, melanomas, essentially all malignancies.
- metastases typically multiple and bilateral.
- occasionally a solitary-appearing
metastasis can mimic a primary lung tumor.

Question 15

What is the normal amound of pleural fluid?

Answer 15

Normally: no more than 15 ml of clear serous
fluid lubricates each pleural cavity.
- pleural fluid formation (mesothelial cells) =
lymphatic resorption.

Question 16

What is pleural effusion?

Answer 16

Increased unilateral or bilateral pleural fluid causing:
- lung compression (atelectasis), chest pain
from pleuritis, dyspnea, cough, fever.

Question 17

What causes pleural effusions?

Answer 17

1. ) Increased fluid production
2. ) Decreased lymphatic resorption
3. ) Hemothorax = vascular rupture

Question 18

What are three mechanisms that cause increased fluid production in the pleural space?

Answer 18

A. Non-inflammatory (transudate):
- increased hydrostatic pressure (CHF).
- decreased osmotic pressure: nephrotic syndrome.
- cirrhosis with ascites: diaphragmatic transit.
- peritoneal dialysis.
- urinothorax.
B. Inflammatory/pleuritic (exudate):
- parapneumonic: bacterial pneumonia, lung abscess, bronchiectasis, viral infection.
- empyema = grossly purulent effusion.
C. Malignant effusion (exudate): involvement of
pleural surfaces by neoplastic cells.

Question 19

What is chylothorax?

Answer 19

Interruption of pulmonary lymphatics:

• from trauma to thoracic duct or mediastinal lymphatic blockage by malignancy
  - pleural fluid triglycerides > 110 mg%.

Question 20

What is the difference between the definitions of transudate vs. exudate?

Answer 20

Three test rule: one or more fulfilled = exudate
(1) pleural fluid protein > 2.9 gm%.
(2) pleural fluid cholesterol > 45 mg%.
(3) pleural fluid LDH > 0.45 x upper limit of normal
serum LDH.

Question 21

What are the possible etiologies of increased pleural fluid?

Answer 21

(1) Most common causes of transudative
effusion (USA) = Left ventricular heart
failure and cirrhosis.
(2) Most common causes of exudative
effusions (USA) = bacterial pneumonia,
malignancy, viral infection, and pulmonary
embolism.
(3) Exudative fluids – require extended work-
up to determine etiology.

Question 22

What are the indications for thoracentesis?

Answer 22

1) New effusion
- exceptions: bilateral effusions in uncomplicated heart failure or small effusions in viral pleurisy.
2) Gross appearance: pale yellow/clear vs. bloody vs. milky vs. purulent vs. brown.
- pleural fluid analysis: WBC/differential,
pH, protein, LDH, glucose.
- additional tests: amylase, cholesterol,
triglycerides, bug stains and culture/PCR,
and CYTOLOGY.

Question 23

What are the three types of pneumothorax?

Answer 23

(1) Primary spontaneous: typically young
patients (many are smokers) - no apparent
lung disease: presumed cause = small
subpleural bleb rupture
(2) Secondary spontaneous – air leak from
underlying lung disease: emphysema,
asthma, cystic fibrosis, TB, pneumonia (esp.
pneumocystis), neoplasia; almost any
chronic lung disease.
(3) Traumatic – penetrating wound, rib fracture,
iatrogenic pleural injury, and mechanical
ventilation.

Question 24

What is the clinical presentation of pneumothorax?

Answer 24

• dyspnea with chest pain localized to side of
  pneumothorax.
• physical exam for large pneumothorax:
  diminished breath sounds and hyper-resonant
  percussion.
• arterial blood gases may be abnormal: hypoxemia and hypercarbia.
• CXR: classic features confirm diagnosis
  - small, self-sealing/resorptive to large/life-
  threatening: tension pneumothorax.

Question 25

What are the two primary pleural tumors?

Answer 25

1) Solitary fibrous tumor
- usually benign/occasionally malignant tumor of submesothelial fibrous tissue.
- may be large (>10cm) and displace lung: surgery alone usually curative.
2) Malignant mesothelioma = Big Bad tumor of pleura:
- 90% related to prior asbestos exposure
- occupational vs. cases with minimal exposure.
- latent period for tumor to develop post
exposure: up to 45 years

Question 26

What is the clinical presentation of malignant mesothelioma?

Answer 26

• Clinical symptoms: chest pain, dyspnea,
  often bloody pleural effusion.
• Chest imaging: unilateral/diffuse pleural
  thickening often associated with effusion and
  calcified pleural plaques: marker for asbestos exposure.
• Histology: epithelioid (carcinoma-like) and/or
  sarcomatous with invasion of chest wall and pericardium.

Question 27

What is the treatment for malignant mesothelioma?

Answer 27

If possible, is aggressive:

-extra-pleural pneumonectomy and/or chemo Rx/radiation Rx.

Question 28

What is the prognosis for malignant mesothelioma?

Answer 28

Usually dismal – long term survival possible only for highly selected patients tolerating radical surgery.
-overall median survival = 12 months.

Question 29

What are the six congenital lung malformations?

Answer 29

1) Congenital pulmonary airway malformation (CPAM)
= most common congenital lung lesion
- cystic features; small risk of malignancy
- neonatal respiratory distress vs. infection vs. incidental discovery later in life.
- often pre-natal diagnosis.
2) Lung agenesis/hypoplasia
3) Tracheal/bronchial anomalies – atresia, stenosis, tracheo-esophageal fistula
4) Congenital lobar overinflation/emphysema: birth up to 6 months.
5) Foregut cysts: hilar/mediastinal – may be found incidentally: bronchogenic vs. esophageal vs. enteric.
6) Pulmonary sequestration - two types:
-Intralobar: aberrant lung tissue within a pulmonary lobe with abnormal connection to native bronchial tree: blood supply from aorta/branches; risk of recurrent infections.
-Extralobar: aberrant lung tissue located outside of normal lung: with blood supply from aorta/branches.

Question 30

What are the three neonatal lung diseases?

Answer 30

(1) Transient tachypnea of newborn:
- late term infants: up to 72 hours.
(2) Persistent pulmonary hypertension:
- term/late term infants.
- multiple associated causes/underlying conditions.
(3) Respiratory distress syndrome (RDS) =
hyaline membrane disease: affects
premature infants: 28 weeks or less (93%)