Morphology of Inflammation

Question 1

Classification of Inflammation

Answer 1

Duration

Distribution

Severity

Morphology

Response of the tissue

All of these can be included as components of a morphologic diagnosis

Question 2

Duration of Inflammation:

Peracute

Answer 2

Begins minutes to hours after insult

Can last for several hours

Prominent vascular changes

Question 3

Duration of Inflammation:

Acute

Answer 3

Begins 4-6 hours insult

Can last for several days

Vascular and early cellular changes

Question 4

Duration of Inflammation:

subacute

Answer 4

Begins several days after insult

Can last for several weeks

Mixed cellular response with decreasing vascular response

Question 5

Duration of Inflammation:

Chronic

Answer 5

Begins several days to weeks after insult

Can last for weeks, months or years

Mononuclear cells and fibrosis with minimal vascular response

Question 6

Distribution of the lesion:

Focal

Answer 6

Single delineated lesion

Question 7

Distribution of the lesion:

Multifocal

Answer 7

Multiple, randomly scattered focal lesions

Question 8

Distribution of the lesion

Locally extensive

Answer 8

A single lesion involving a large area of tissue

Question 9

Distribution of the lesion:

Diffuse

Answer 9

Lesion involving the entire tissue in which it is found

Question 10

Severity of the lesion:

Mild

Answer 10

Vascular change, mild cellular change, no tissue destruction

Question 11

Severity of the lesion:

Moderate

Answer 11

Prominent vascular and cellular change with some tissue destruction

Question 12

Severity of the lesion:

Severe

Answer 12

Extension of vascular and cellular changes with extensive tissue destruction

Question 13

Exudate or Cell type

Answer 13

• Common classification include:
  
  • serous
  • Catarrhal
  • Fibrinous
  • Purulent
  • Hemorrhagic
  • Eosinophilic
  • Lymphocytic
  • Granulomatous

Question 14

Serous Inflammation

Answer 14

• Accumulation of serum-fluid
• Causes include:
  
  • Joint trauma
  • Early response to bacterial and viral infection
  • mild chemical irritant
  • certain insect bites
• Effects include
  
  • dilution of the offending agent
  • Excessive fluid can interfere with tissue function

Question 15

Serous Inflammation:

Morphology:

Gross Appearance

Answer 15

• Watery fluid within body cavities or tissues

Question 16

Serous Inflammation:

Morphology:

Histological

Answer 16

Homogenous pink fluid

Question 17

Catarrhal inflammation:

Answer 17

• Presence of large amounts of mucus
• Causes include:
  
  • mild upper respiratory viral infections
  • mild irritants
• Effects include:
  
  • Protection of mucosal surfaces
  • Dilution of the offending agent

Question 18

Catarrhal Inflammation:

Morphology:

Gross

Answer 18

• Clear, slimy film that covers a mucosal surface
  
  • this can appear as shreds and clumps when it is partially dehydrated

Question 19

Catarrhal Inflammation:

Morphology:

Histological

Answer 19

• Pale, blue material that covers mucosal epithelium
• mucus producing cells are increased in size and number

Question 20

Fibrinous Inflammation

Answer 20

• Presence of a large amount of fibrin
• Casuses include:
  
  • bacterial infections
  • Certain viral infections
  • Burns
• Effects include
  
  • protection of underlying tissues
  • Prevention of blood loss
  • A scaffold for subsequent formation of fibrous tissue

Question 21

Fibrinous Inflammation:

Morphology:

Gross

Answer 21

Yellowish adhesive material that can occur as a granular covering over a tissue, to thick sheets clumps or fine

Question 22

Fibrinous Inflammation:

Morphology:

Histological

Answer 22

Fibrillar, web-like eosinophilic material

Question 23

Purulent Inflammation

Answer 23

• Presence of large numbers of neutrophils
• Causes include:
  
  • Certain types of bacteria
  • Certain chemiccal irritants
• Effects include
  
  • Defense against infectious agents
  • Production of pro-inflammatory agents/toxins
  • Sometimes, interference with tissue functions

Question 24

Purulent Inflammation:

Morphology:

Gross

Answer 24

Viscous to watery, cream-colored materail on mucosal surfaces or within tissues

Question 25

Purulent Inflammation: Morphology Histological

Answer 25

Large numbers of neutrophils are present, often accompanied by fibrin and inflammatory debris

Question 26

Purulent Inflamamtion: Abscess

Answer 26

* An abscess is a localized and confined accumulation of neutrophils and liquefied debris * represents a failure of acute inflammation to remove the inflammatory stimulus * Chronic lesions * mature abscesses can take several weeks to form * It has a fibrous capsule * initially the capsule is very thin, but can thicken over time * Walled off from normal adjacent tissue * Can act as a space occupying mass and interfere with tissue/organ function

Question 27

Hemorrhagic Inflammation

Answer 27

* Presence of large amounts of hemorrhage at an inflammatory site * Causes include: * Agents that cause vascular injury * highly virulent infections agents * Certain chemicals * Effects include: * typically arises quickly * Often associated with more severe inflammation

Question 28

Hemorrhagic Inflammation: Morphology: Gross

Answer 28

The inflamed mucosa or tissue is deep red and associated exudate is red-tinged

Question 29

Hemorrhagic Inflammation: Morphology: Histological

Answer 29

Large numbers of erythrocytes are present in the inflammatory region

Question 30

Eosinophilic Inflammation

Answer 30

* Presence of Large numbers of eosinophils * Causes include: * Hypersensitivity reactions * Parasitic Infections * Effects Include: * Mediates local or systemic hypersensitivity reactions

Question 31

Eosinofilic Inflammation: Morphology: Gross

Answer 31

Affected tissue may have a gray to greenish gray appearance

Question 32

Eosinophilic Inflammation: Morphology: Histological

Answer 32

Affected tissue contains large numbers of eosinophils

Question 33

Lymphocytic Inflammation:

Answer 33

* Presence of large numbers of lymphocytes * Causes include: * certain viral infections * Chronic bacterial and fungal infections * Immunological reactions * Effects include: * Immunological response to antigens * Important component of chronic inflammation

Question 34

Lymphocytic Inflammation: Morphology: Gross

Answer 34

Not often evident grossly, but may give affected tissue a whitish-appearance

Question 35

Lymphocytic Inflammation: Morphology: Histological

Answer 35

Numerous lymphocytes are present either indivdually or in nodular aggregates

Question 36

Granulomatous Inflammation

Answer 36

* Presence of large numbers of macrophages * Causes include * persistent bacterial infections * most fungi * certain parasites * foreign bodies * Effects include: * associated with chornic, difficult to manage inflammatory agents * Can form solid masses and interfere with tissue function

Question 37

Granulomatous Inflammation: Morphology: Gross

Answer 37

This can occur as diffuse thickening of an affected tissue, or the formation of firm nodules or masses

Question 38

Granulomatous inflammation: Morphology: Histological

Answer 38

Numerous macrophages are present along with cells derived from macrophages, and lymphocytes and plasma cells

Question 39

Granuloma Morphology

Answer 39

* Typical granulomas consist of: * a central zone of caseous necrosis * A zone of epithelioid macrophages and giant cells * Zone of lymphocytes * Outer zone of fibroblasts and collagen * There are many variation depending on the age of the granuloma and the inciting stimulus * some lack a central necrotic core * Some have minimal fibrosis around their border

Question 40

Response of the Tissue: Alterative chages

Answer 40

necrotizing ulcerative atrophic fibrosing

Question 41

Response of the Tissue Proliferative changes

Answer 41

hyperplastic hypertrophic