Morphologic Patterns of Inflammation
Acute Inflammation
dilation of small blood vessels
accumulation of leukocytes and fluid in the extravascular tissue
Classification according to the morphologic appearance:
Non-suppurative Inflammation
Catarrhal inflammation
Serous inflammation
Fibrinous inflammation
Hemorrhagic inflammation
Membranous/pseudo-membranous inflammation
Necrotizing (gangrenous) inflammation
Allergic inflammation
Suppurative Inflammation
Localized:
Abscess inflammation
Furuncle
Carbuncle
Diffuse:
Cellulitis
Acute Non-suppurative Inflammation
without pus formation
Catarrhal inflammation
excess mucus secretion due to inflammation of mucus membranes
Site: mucous membranes
Example: common cold (rhinovirus), influenza
Gross appearance: congestion, edema, mucus secretion
==Microscopic examination: ==
blood vessel dilation, congested (filled with blood)
excess mucus on epithelial surface
few or absence of neutrophils
Serous Inflammation
watery protein-poor fluid (effusion)
typically does not contain microbes or large numbers of leukocytes
Derived from:
serum
mesothelial cell secretion
Site: spaces created by cell injury or into body cavities lined by the peritoneum, pleura, or pericardium.
Examples: skin blister (burn), pleural effusion (pleurisy)
Gross appearance: congested surface, watery effusion
Fibrinous Inflammation
fibrinous exudate
Site: lining of body cavities, (meninges, pericardium, and pleura)
Example: serosal surfaces (fibrinous pericarditis)
Hemorrhagic Inflammation
exudate rich in red blood cells
Example: severe capillary damage (anthrax, plague)
Membranous/Pseudo-membranous Inflammation
necrotic membrane on mucus surfaces
Example: diphtheritic pharyngitis, bacillary dysentery
Gross appearance: greyish membrane on mucosal surface
==Microscopic examination: ==
necrotic mucosa
fibrin and inflammatory cells adherent to mucosal surface
Necrotizing (Gangrenous) Inflammation
Example: gangrenous acute appendicitis, gangrene of the foot
Allergic Inflammation
Example: bronchial asthma
==Microscopic examination: ==
exudate rich in eosinophils
extensive edema
Acute Suppurative (Purulent) Inflammation
purulent exudate (pus): fluid, necrotic cells, and pus cells (dead neutrophils)
Localized
abscess formation
Organisms: pyogenic bacteria (Staphylococcus aureus)
Diffuse
Cellulitis: diffuse suppurative inflammation
Site: subcutaneous tissue (orbit, pelvis, scrotum, mediastinum)
Organisms: Streptococcus hemolyticus
Chronic Inflammation
Chronic “non-specific” or diffuse inflammation
Chronic specific inflammation
Diffuse Non-specific Inflammation
diffuse chronic inflammatory cell infiltrate
Example: chronic pyelonephritis, chronic cholecystitis
Chronic Specific Inflammation (Granuloma)
caseating granulomatous inflammation
Example: Tuberculosis
non-caseating granulomatous inflammation
Example: leprosy, syphilis, schistosomiasis, sarcoidosis and foreign body granuloma
Morphologic Patterns of Inflammation
Acute Inflammation
dilation of small blood vessels
accumulation of leukocytes and fluid in the extravascular tissue
Classification according to the morphologic appearance:
Non-suppurative Inflammation
Catarrhal inflammation
Serous inflammation
Fibrinous inflammation
Hemorrhagic inflammation
Membranous/pseudo-membranous inflammation
Necrotizing (gangrenous) inflammation
Allergic inflammation
Suppurative Inflammation
Localized:
Abscess inflammation
Furuncle
Carbuncle
Diffuse:
Cellulitis
Acute Non-suppurative Inflammation
without pus formation
Catarrhal inflammation
excess mucus secretion due to inflammation of mucus membranes
Site: mucous membranes
Example: common cold (rhinovirus), influenza
Gross appearance: congestion, edema, mucus secretion
==Microscopic examination: ==
blood vessel dilation, congested (filled with blood)
excess mucus on epithelial surface
few or absence of neutrophils
Serous Inflammation
watery protein-poor fluid (effusion)
typically does not contain microbes or large numbers of leukocytes
Derived from:
serum
mesothelial cell secretion
Site: spaces created by cell injury or into body cavities lined by the peritoneum, pleura, or pericardium.
Examples: skin blister (burn), pleural effusion (pleurisy)
Gross appearance: congested surface, watery effusion
Fibrinous Inflammation
fibrinous exudate
Site: lining of body cavities, (meninges, pericardium, and pleura)
Example: serosal surfaces (fibrinous pericarditis)
Hemorrhagic Inflammation
exudate rich in red blood cells
Example: severe capillary damage (anthrax, plague)
Membranous/Pseudo-membranous Inflammation
necrotic membrane on mucus surfaces
Example: diphtheritic pharyngitis, bacillary dysentery
Gross appearance: greyish membrane on mucosal surface
==Microscopic examination: ==
necrotic mucosa
fibrin and inflammatory cells adherent to mucosal surface
Necrotizing (Gangrenous) Inflammation
Example: gangrenous acute appendicitis, gangrene of the foot
Allergic Inflammation
Example: bronchial asthma
==Microscopic examination: ==
exudate rich in eosinophils
extensive edema
Acute Suppurative (Purulent) Inflammation
purulent exudate (pus): fluid, necrotic cells, and pus cells (dead neutrophils)
Localized
abscess formation
Organisms: pyogenic bacteria (Staphylococcus aureus)
Diffuse
Cellulitis: diffuse suppurative inflammation
Site: subcutaneous tissue (orbit, pelvis, scrotum, mediastinum)
Organisms: Streptococcus hemolyticus
Chronic Inflammation
Chronic “non-specific” or diffuse inflammation
Chronic specific inflammation
Diffuse Non-specific Inflammation
diffuse chronic inflammatory cell infiltrate
Example: chronic pyelonephritis, chronic cholecystitis
Chronic Specific Inflammation (Granuloma)
caseating granulomatous inflammation
Example: Tuberculosis
non-caseating granulomatous inflammation
Example: leprosy, syphilis, schistosomiasis, sarcoidosis and foreign body granuloma