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Question 434
Pathology → General
Classification
Question
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Histological examination of an intravascular mass demonstrates alternating pale platelet-rich and darker red-cell-rich layers. Which interpretation is most appropriate?
Question Stem
Select the single best answer.
Options
A
The lesion represents postmortem clotting
B
The lesion is an organised embolus that has undergone complete fibrinolysis
C
The appearances are characteristic of Lines of Zahn in a thrombus formed in flowing blood
D
The finding establishes inherited protein C deficiency
E
The lesion represents fibrinoid necrosis of the vessel wall
Explanation
Lines of Zahn are alternating pale platelet-rich and darker red-cell-rich layers within a thrombus and reflect formation in flowing blood.
Option Validity
A) The laminated pattern described is characteristic of antemortem thrombosis in flowing blood rather than simple postmortem clotting.
B) Complete fibrinolysis would resolve the thrombus rather than produce the characteristic alternating layers described.
D) An inherited thrombophilia may predispose to thrombosis, but Lines of Zahn do not identify a specific thrombophilic defect.
E) Fibrinoid necrosis is a pattern of vessel-wall injury and is distinct from the laminated structure of an intravascular thrombus.
Further Reading
Saxena R. Textbook for MRCOG-1. Chapter 5: Pathology. General Pathology, pp.161–175.