Haemodynamic disturbances
Here is an example of a "nutmeg" liver seen with chronic passive congestion of the liver. Note the dark red congested regions that represent accumulation of RBC's in centrilobular regions. the natural nutmeg is at right.Microscopically, the nutmeg pattern results from congestion around the central veins, as seen here. This is usually due to a "right sided" heart failure.
Pulmonary congestion with dilated capillaries and leakage of blood into alveolar spaces leads to an increase in hemosiderin-laden macrophages, as seen here.
Mural thrombi of the heart
Coronary artery thrombosisCross section through the coronary artery showing the thrombus obstructing the whole lumen.
Microscopic appearance of thrombus' the line of Zahn’ These lines represent layers of red cells, platelets, and fibrin which are laid down in the vessel as the thrombus form.
Fates of thrombus : propagation, resolution, organization, recanalization & embolization. Note the organization & the recanalization of the thrombus in these two slides.
Atheroma with organized thrombus: the thrombus here is replaced by granulation tissue.
Organized thrombus at high power view, note the area of granulation tissue replacing the thrombusPulmonary embolism
Pulmonary embolus obstructing the main pulmonary arterySaddle embolus of main pulmonary trunk
This is the microscopic appearance of a pulmonary thromboembolus in a large pulmonary artery. There are interdigitating areas of pale pink and red that form the "lines of Zahn" characteristic for a thrombus .
Paradoxical embolus through a patent foramen ovale
Pulmonary infarction produced by a medium-sized thromboembolus to the lung. This infarction forms a wedge- shaped area & has begun to organize at the margins.Infarctions of the spleen produce wedge –shaped pale areasAnd caused by obstruction of spleenic artery