Chapter 15: The Lung - Pleura

Question 1

Radiation used in therapy for tumors in the lung or mediastinum often causes what type of pleuritis?

Answer 1

Serofibrinous pleuritis

Question 2

A purulent pleural exudate (empyema) usually results from what?

Answer 2

Bacterial or mycotic seeding of the pleural space; by contiguous spread from intrapulmonary infections, but may also be from lymphatic or hematogenous dissemination

Question 3

Which inflammatory-type of pleural effusion is characterized by loculated, yellow-green, creamy pus composed of masses of neutrophils admixed with other leukocytes?

Answer 3

Empyema

Question 4

Empyema of the lungs may resolve, but more often the exudate organizes into what; causes what complications?

Answer 4

• Organizes –> dense, tough fibrous adhesions
• Frequently obliterate the pleural space or envelope the lungs
• Restricting pulmonary expansion

Question 5

Which type of pleuritis is manifested by sanguineous inflammatory exudates?

Answer 5

Hemorrhagic pleuritis

Question 6

Hemorrhagic pleuritis is found in what 3 settings?

Answer 6

• Hemorrhagic diatheses
• Rickettsial diseases
• Neoplastic involvement

Question 7

What are the 3 major mechanisms underlying transudative pleural effusions; examples?

Answer 7

• ↑ hydrostatic pressure; “overflow” from the lung interstitium = CHF
• ↓ plasma oncotic pressure = nephrotic syndrome
• Movement of transudative ascitic fluid thru the diaphargam = cirrhosis

Question 8

What are the 2 major mechanisms underlying exudative pleural effusions; some examples?

Answer 8

• Inflammation –> infection (TB, pneumonia), PE (infarction), CT disease (SLE, RA), adjacent to subdiaphragmatic disease (pancreatitis, subphrenic abscess)
• Malignancy

Question 9

What is the arrow indicating on this CT scan?

Answer 9

Pleural effusion

Question 10

How will a pleural effusion associated with mediastinal carcinomatosis appear grossly due to decreased lymph drainage?

Answer 10

Milky chylous effusion = Chylothorax

Question 11

Noninflammatory collections of serous fluid within pleural cavities are known as what; appear how grossly?

Answer 11

Hydrothorax; clear fluid that is straw colored

Question 12

What is the most common cause of hydrothorax; other causes?

Answer 12

• Most common = Cardiac failure
• Also, renal failure and cirrhosis

Question 13

Hemothorax is a usually fatal complication associated with what?

Answer 13

Ruptured aortic aneurysm or vascular trauma

Question 14

Pneumothorax is most commonly associated with what 3 conditions?

Answer 14

• Emphysema
• Asthma
• Tuberculosis

Question 15

Spontaneous idiopathic penumothorax most often occurs in which age group and is due to what?

Answer 15

• Young patients
• Rupture of small, peripheral, usually apical subpleural blebs

Question 16

Typical course of spontaneous idiopathic penumothorax; and likelihood or recurrence?

Answer 16

• Typically subsides spontaneously as air is resorbed
• Reccurent attacks = common

Question 17

When injury to chest wall results in a one-way valve allowing air into the pleural space, but not out, effectively acting as a pump and ↑ pressure, this is known as?

Answer 17

Tension pneumothorax

Question 18

A tension pneumothorax is due to expansion of which structure?

Answer 18

Chest wall (not lungs per se)

Question 19

What is one of the more devastating consequences of Empyema that makes it hard to treat and hard to clear out?

Answer 19

Creating loculations –> web-like traps for fluid

Question 20

What type of pneumothorax is this?

Answer 20

Primary pneumothorax

Question 21

What type of pneumothorax is this?

Answer 21

Tension pneumothorax

Question 22

Which type of pneumothorax is associated with pleural cavity pressure is < atmospheric pressure?

Pleural cavity pressure > atmospheric pressure?

Answer 22

• Pleural cavity < atmospheric = primary pneumothorax
• Pleural cavity > atmospheric = tension pneumothorax

Question 23

In spontaneous idiopathic pneumothorax which direction will the trachea shift?

Answer 23

TOWARD the side of collapse

Question 24

What is more common primary pleural tumors or secondary tumors from metastasis?

Answer 24

Secondary from metastasis

Question 25

The most frequent metastatic malignancies of the pleura arise from which 2 sites?

Answer 25

**Breast** and **lung**

Question 26

In most metastatic involvements of the pleura what type of effusion follows?

Answer 26

**Serous** or **sero-sangioneous** often containing **neoplastic cells**

Question 27

Which soft-tissue tumor has a propensity to occur in the pleura is often attached to the surface by a pedicle?

Answer 27

Solitary fibrous tumor

Question 28

Which immunostaining features of solitary fibrous tumors are helpful in distinguishing these tumors from malignant mesotheliomas?

Answer 28

**CD34+** and **keratin-negative**

Question 29

What do solitary fibrous tumors show microscopically?

Answer 29

**Whorls** of **reticulin** and **collagen** fibers w/ interspersed **spindle cells** resembling **fibroblasts**

Question 30

Solitary fibrous tumors are **highly** associated with a cryptic inverion of which chromosome and this creates which **fusion** gene unique to this tumor?

Answer 30

Chromosome **12** ---\> ***NAB2-STAT6*** fusion gene

Question 31

Homozygous deletion of which tumor suppressor gene occurs in about 80% of mesothelioma; involves which chromosome?

Answer 31

***CDKN2A/INK4-α*** on chromosome **9p**

Question 32

How does malignant mesothelioma appear grossly?

Answer 32

Affected lung is **ensheathed** by a **thick layer** of **soft, gelatinous**, **grayish-pink** tumor tissue

Question 33

What are the 3 variants of growth that can be seen microscopically with mesothelioma?

Answer 33

- Epithelioid - Sarcomatoid - Mixed

Question 34

Epithelioid type of mesothelioma resembles adenocarcinoma; how can it be differentiated via immunohistochemical stains for which 5 markers?

Answer 34

- (+) **Keratin** - (+) **Calretinin** - (+) **Wilms tumor 1 (WT-1)** - (+) **Cytokeratin 5/6** - (+) **D2-40**

Question 35

The mesenchymal type of mesothelioma (sarcomatoid type) appears as what type of sarcoma and resembles?

Answer 35

**Spindle** **cell** sarcoma, resembling **fibrosarcoma**

Question 36

Sarcomatoid mesotheliomas may only stain positive for which marker?

Answer 36

Keratin

Question 37

What are the typical presenting features of malignant mesothelioma?

Answer 37

- **Chest pain** - **Dyspnea** - **Recurrent pleural effusions\*\***

Question 38

Malignant mesothelioma often invades lung directly and commonly metastasizes to which LN and organs?

Answer 38

- **Hilar** LN's - Eventually --\> **liver** and other distant organs

Question 39

What is the prognosis of malignant mesothelioma?

Answer 39

50% die within 12 months; few survive longer than 2 years

Question 40

What are found in increased numbers in the lungs of patients with mesothelioma?

Answer 40

**Asbestos bodies** and **asbestos plaques**