By Dr Abiodun Mark. A

Identify the slide.

What is going on with the organ?

Congested lungs. This is a gross photograph of lungs that are distended and red. The reddish coloration of the tissue is due to congestion. Some normal pink lung tissue is seen at the edges of the lungs (arrows).

Identify the organ? What is the pathologic process here?

NUTMEG LIVER. This is a gross photograph of a liver demonstrating chronic passive congestion. Note the accentuation of the centrilobular pattern evidenced by the dark-brown-staining areas in this tissue.

Liver congestion. This is a high-power photomicrograph of the central vein illustrating congestion and some loss of liver parenchymal cells. A mild increase in connective tissue around the central vein is evident in this section.

Cardiac cirrhosis If chronic hepatic passive congestion continues for a long time, a condition called "cardiac cirrhosis" may develop in which there is fibrosis bridging between central zonal regions, as shown below, so that the portal tracts appear to be in the center of the reorganized lobule. This process is best termed "cardiac sclerosis" because, unlike a true cirrhosis, there is minimal nodular regeneration.

Identify the slide.

Thrombosis of the coronary artery. This is a low-power photomicrograph of thrombosed coronary artery. (A thrombus is a solid mass resulting from the aggregation of blood constituents within the vascular system) (1) completely occludes the vessel. Note the layering of the thrombus. The fibrous cap is ruptured (arrow) and there is hemorrhage into the atherosclerotic plaque. Note the cholesterol crystals in the plaque.

What can you see in this organ?

Mural (Non occlusive) Thrombus. This is a gross photograph of the heart from this case demonstrating the well-formed thrombus tightly attached to the myocardium near the apex of the left ventricle. A thrombus is a solid mass resulting from the aggregation of blood constituents within the vascular system.

More on mural thrombi 2. This higher-power photomicrograph shows the border between the thrombus on the right (1) and the endocardium on the left (2). There is a line of inflammatory cells at this interface (arrow).

Lines of Zahn. These are "lines of Zahn" which are the alternating pale pink bands of platelets with fibrin and red bands of RBC's forming a true thrombus. Lines of Zahn are unique to cardiac and arterial thrombi.

What is the pathology here?

Venous thrombi. – Form in slow-moving blood. – Have a high proportion of trapped red cells in relation to platelet/fibrin therefore they are red, soft gelatinous with poor lamination. – They grow (propagate) towards the direction of the heart. – They may detach to produce emboli – Thrombi of infected veins are called thrombophlebitis. – Almost all venous thrombi occlude the lumen and prevent blood flow (Occlusive thrombi)

Identify the slide?

Pulmonary thromboembolus. This pulmonary embolus is adherent to the pulmonary arterial wall. If the patient survives, the thromboembolus will organize and, for the most part, be removed.

What the mechanism behind this pathology?

Pulmonary thromboembolus A pulmonary thromboembolus travels from a large vein in the leg up the inferior vena cava, through the right side of the heart, and to the main pulmonary arteries as they branch. Such thrombi embolize most often from large veins in the legs and pelvis where thrombi may form with stasis and/or inflammation.

Identify the slide.

Myocardial Infarction Infarction of many internal organs leads to a "pale" infarct from loss of the blood supply, resulting in coagulative necrosis. Shown here is a myocardial infarction from occlusion of a major coronary artery, here the left anterior descending artery

Identify the organ? What is the pathologic process here?

Splenic infarct. Here are splenic infarcts in a patient with infective endocarditis. These infarcts are typical of ischemic infarcts: they are based on the capsule, pale, and wedge-shaped. The remaining splenic parenchyma appears dark red. With most wedged shaped infarcts, the occluded vessel marks the apex and the organ periphery marks the base.

Identify the organ? What is the pathology here?

Pulmonary infarction Occlusion of small pulmonary arteries has no major immediate effect. Occlusion of a medium-sized branch of pulmonary artery can lead to a pulmonary infarction in a person with compromised cardiac or respiratory status. A pulmonary infarct is hemorrhagic because of the dual blood supply: some blood still flows from the non-occluded bronchial arteries which mainly supply blood to interstitium, but do not prevent the infarction

Petechial hemorrhages on the myocardium. Here are petechial hemorrhages seen on the epicardium of the heart. Petechiae (pinpoint hemorrhages) represent bleeding from small vessels and are classically found when a coagulopathy is due to a low platelet count. They can also appear following sudden hypoxia.

Identify the organ? What is the pathologic condition here?

Skin eccymoses. The blotchy areas of hemorrhage in the skin are called ecchymoses (singular ecchymosis)

What form of embolus is this?

Saddle embolus. Autopsy photo from a patient who died suddenly from a large “saddle” embolus. The embolus is lodged at the bifurcation of the main pulmonary artery into the right and left pulmonary arteries, largely obstructing the flow of blood to the lungs.

Paradoxical Embolism.

Muchas gracias Al final.