Morphology of Thrombi

Question 1

Define pathology and morphology

Answer 1

• the precise study and diagnosis of disease

- study of shape, form, or structure; 1 facet of pathology

Question 2

__________ triad in thrombosis components.

Answer 2

• Virchow’s

- endothelial injury**, hypercoagulability, abnormal blood flow (stasis or turbulence)

Question 3

What make up the lines of Zahn?

Answer 3

• white (pink on H&E): platelets and fibrin

- red (red on H&E): trapped RBCs

Question 4

Venous vs. Arterial thrombi: where they form, why they form, their “color”

Answer 4

• Location: arterial are most common in coronary, cerebral, and femoral arteries while venous form in lower extremities, upper extremities, pelvic plexi, dural sinuses, portal and hepatic vein
• Cause: arterial are due to endothelial injury and/or turbulence and can be assoc. with ruptured plaque, vasculitis, trauma; venous are due to stasis
• Color: arterial are called white thrombi due to increased role of platelets while venous are called red thrombi due to increased rol of RBC trapping

Question 5

4 potential fates of thrombi

Answer 5

1. propagation: progress of growth
2. embolization: dislodge and travel via blood to another site
3. dissolution: fibrinolysis of young break thrombi
4. organization and recanalization: older thrombi organized and new channels form to reestablish blood flow

Question 6

Saddle Embolus

Answer 6

-thromboembolus (usually due to DVT) that ends at bifurcation of pulmonary artery

Question 7

Venous vs. arterial thromboemboli

Answer 7

-Venous thrombi usually cause pulmonary embolism while arterial cause systemic thromboemboli that affect end organs like limbs, brain, GI and other viscera

Question 8

2 parts of postmortem clot

Answer 8

1. RBCs: current jelly

2. Coagulated plasma: chicken fat

Question 9

2 main features important in identifying a thrombus

Answer 9

1. Lines of Zahn

2. Attachment to vessel wall

Question 10

Describe main differences between postmortem clot and thrombus

Answer 10

1. post mortem clots result from separation and settling of blood components with the cessation of circulation/lack of flow
2. softer consistency, lack lines of Zahn, non-adherent