PATHOMORPHOLOGY
MOHAMED GHADRI
, HEMODYNAMIC DISORDERS 1
• Hemorrhage – The outflow of blood due to damaged or ruptured vessels or defective
clot formation.
- Petechiae: Minute (1-2 mm), due to thrombocytopenia, loss of vascular wall support
and defective platelet function.
- Purpura: Slightly larger (3-5 mm), due to vasculitis, trauma and increased vascular
fragility
- Ecchymoses: Larger (1-2 cm), A bruise caused by blood leaking from blood vessels
• Saccular aneurysm is most commonly found in the anterior portion of circle of wills
- Epidural hemorrhage is usually
because of an abnormality in the Middle
meningeal artery.
• RECENT BRAIN HAEMORRHAGE:
• Brain stroke is commonly a result from arterial hypertension.
• Middle cerebral artery is most commonly ruptured therefore the internal capsule
and adjacent basal ganglia are most frequent site of cerebral hemorrhage.
• Macroscopically; The affected hemisphere is swollen, showing gyri flattening.
• INVETERATED (OLD) BRAIN HAEMORRHAGE:
• The blood mixed with necrotic brain mass is removed by macrophages.
- In case of RBC, their heme is transformed into brown hemosiderin.
- In case of cerebral lipids, the macrophages accumulate them in the cytoplasm
which becomes foamy.
• The removal of destroyed masses results in postapopletic cavern.
,• CHRONIC PASSIVE LIVER CONGESTION (NUTMEG LIVER):
• An increase in blood volume in dilated vessels is known as Congestion.
• The impairment of blood outflow is known as Passive (venous) congestion.
• Nutmeg liver is subsequent to Right-sided heart failure or compression/obstruction
of IVC and hepatic veins that leads to hypoxia of hepatocytes.
• Macroscopically; Central areas are red and slightly depressed compared with the
surrounding tan viable parenchyma forming the (nutmeg liver) pattern.
• Peripheral lobules show fatty degeneration (hepatocytes filled with fat are round-
shaped and appear empty, since lipids are dissolved during routine preparation of
specimen.
• Nutmeg contains myristicin, a monoamine oxidase inhibitor and psychoactive
substance that can induce convulsions, nausea and dehydration.
• PULMONARY BROWN INDURATION:
• Chronic passive congestion of lungs is commonly due to Left-sided heart failure or
mitral valve stenosis and it leads to fibrosis which is due to stimulated collagen
formation.
• Macroscopically; lungs are brown and firm with thicker interalveolar septa.
• PULMONARY OEDEMA:
• A condition characterized by excessive accumulation of fluid within the lungs
• Results from Left-sided heart failure and mitral valve stenosis
• Macroscopically; lungs are enlarged, heavy and pit on pressure
• Microscopically; Alveolar septa show congested capillary whereas alveolar spaces are
filled with eosin and empty round spaces are present within intra-alveolar fluid they
represent air bubbles.
- Hemodynamic edema:
Is due to increased hydrostatic pressure and decreased oncotic pressure and
hypoalbuminemia
- Edema due to microvascular injury:
Is due to increased capillary permeability that can be because of pneumonia, inhaled
gases, liquid aspiration and drugs such as bleomycin or heroin
- Edema of undetermined origin:
For example; neurogenic (CNS trauma)
• Transudate is protein and cell poor, but Exudate is protein and cell rich
, HEMODYNAMIC DISORDERS 2
• Blood Clot is a mas of coagulated blood that is homogenous and lacks attachment to
the endothelial wall
• Thrombus is a pathological mass of clotted blood formed in cardiovascular system
and its closely attached to the vessel wall
• Thrombosis is pathological, it designates phenomenon of intravital blood coagulation
Virchow triad
FATE OF THROMBUS:
- Propagation
- Embolization
- Dissolution
- Organization: thrombus replacement by connective tissue
- Recanalization: Restoring blood flow by capillary dilation
• Organized thrombus:
- Microscopically; vessels lumen is obstructed and capillaries are dilated
• Embolism:
• Venous emboli originate from deep leg vein thrombi above the knee level and its
also known as paradoxical emboli as it causes a defect in systemic circulation
• Saddle pulmonary embolus is due to a large blood clot that lodges at the bifurcation
of pulmonary arteries
• PULMONARY BONE MARROW EMBOLISM:
• It is the most frequent fat embolism that leads to fractures of long bones and soft
tissue trauma and burns
• Macroscopically; lungs are dark red and edematous and microscopically; fat globules
are present in the alveoli
MOHAMED GHADRI
, HEMODYNAMIC DISORDERS 1
• Hemorrhage – The outflow of blood due to damaged or ruptured vessels or defective
clot formation.
- Petechiae: Minute (1-2 mm), due to thrombocytopenia, loss of vascular wall support
and defective platelet function.
- Purpura: Slightly larger (3-5 mm), due to vasculitis, trauma and increased vascular
fragility
- Ecchymoses: Larger (1-2 cm), A bruise caused by blood leaking from blood vessels
• Saccular aneurysm is most commonly found in the anterior portion of circle of wills
- Epidural hemorrhage is usually
because of an abnormality in the Middle
meningeal artery.
• RECENT BRAIN HAEMORRHAGE:
• Brain stroke is commonly a result from arterial hypertension.
• Middle cerebral artery is most commonly ruptured therefore the internal capsule
and adjacent basal ganglia are most frequent site of cerebral hemorrhage.
• Macroscopically; The affected hemisphere is swollen, showing gyri flattening.
• INVETERATED (OLD) BRAIN HAEMORRHAGE:
• The blood mixed with necrotic brain mass is removed by macrophages.
- In case of RBC, their heme is transformed into brown hemosiderin.
- In case of cerebral lipids, the macrophages accumulate them in the cytoplasm
which becomes foamy.
• The removal of destroyed masses results in postapopletic cavern.
,• CHRONIC PASSIVE LIVER CONGESTION (NUTMEG LIVER):
• An increase in blood volume in dilated vessels is known as Congestion.
• The impairment of blood outflow is known as Passive (venous) congestion.
• Nutmeg liver is subsequent to Right-sided heart failure or compression/obstruction
of IVC and hepatic veins that leads to hypoxia of hepatocytes.
• Macroscopically; Central areas are red and slightly depressed compared with the
surrounding tan viable parenchyma forming the (nutmeg liver) pattern.
• Peripheral lobules show fatty degeneration (hepatocytes filled with fat are round-
shaped and appear empty, since lipids are dissolved during routine preparation of
specimen.
• Nutmeg contains myristicin, a monoamine oxidase inhibitor and psychoactive
substance that can induce convulsions, nausea and dehydration.
• PULMONARY BROWN INDURATION:
• Chronic passive congestion of lungs is commonly due to Left-sided heart failure or
mitral valve stenosis and it leads to fibrosis which is due to stimulated collagen
formation.
• Macroscopically; lungs are brown and firm with thicker interalveolar septa.
• PULMONARY OEDEMA:
• A condition characterized by excessive accumulation of fluid within the lungs
• Results from Left-sided heart failure and mitral valve stenosis
• Macroscopically; lungs are enlarged, heavy and pit on pressure
• Microscopically; Alveolar septa show congested capillary whereas alveolar spaces are
filled with eosin and empty round spaces are present within intra-alveolar fluid they
represent air bubbles.
- Hemodynamic edema:
Is due to increased hydrostatic pressure and decreased oncotic pressure and
hypoalbuminemia
- Edema due to microvascular injury:
Is due to increased capillary permeability that can be because of pneumonia, inhaled
gases, liquid aspiration and drugs such as bleomycin or heroin
- Edema of undetermined origin:
For example; neurogenic (CNS trauma)
• Transudate is protein and cell poor, but Exudate is protein and cell rich
, HEMODYNAMIC DISORDERS 2
• Blood Clot is a mas of coagulated blood that is homogenous and lacks attachment to
the endothelial wall
• Thrombus is a pathological mass of clotted blood formed in cardiovascular system
and its closely attached to the vessel wall
• Thrombosis is pathological, it designates phenomenon of intravital blood coagulation
Virchow triad
FATE OF THROMBUS:
- Propagation
- Embolization
- Dissolution
- Organization: thrombus replacement by connective tissue
- Recanalization: Restoring blood flow by capillary dilation
• Organized thrombus:
- Microscopically; vessels lumen is obstructed and capillaries are dilated
• Embolism:
• Venous emboli originate from deep leg vein thrombi above the knee level and its
also known as paradoxical emboli as it causes a defect in systemic circulation
• Saddle pulmonary embolus is due to a large blood clot that lodges at the bifurcation
of pulmonary arteries
• PULMONARY BONE MARROW EMBOLISM:
• It is the most frequent fat embolism that leads to fractures of long bones and soft
tissue trauma and burns
• Macroscopically; lungs are dark red and edematous and microscopically; fat globules
are present in the alveoli
