Lungs are distended and red. The reddish coloration of the tissue is due to congestion (alveolar capillaries are engorged with blood). Some normal pink tissue is seen at the edge of the lung (arrows).

1
Lungs are distended and red. The reddish
coloration of the tissue is due to congestion
(alveolar capillaries are engorged with blood).
Some normal pink tissue is seen at the edge of
the lung (arrows).
2
Acute pulmonary congestion and edema A frothy
exudate fills the bronchus (arrow).
3
Pulmonary congestion and edema Frothy exudate
being extruded from the lung tissue.
4
Pulmonary congestion and edema The lung section
has a pale red color indicating proteinaceous
material within the lung.
5
Arrows Edema fluid within the alveoli 1
Thickened pleura
6
Arrows Edema filled alveoli
7
1 Edema fluid within the alveoli Arrows
Congestion (RBCs) in the alveolar capillaries
8
Liver Chronic Passive Congestion Note the
accentuation of the centrilobar pattern evidenced
by the dark brown staining areas in this tissue.
9
Liver Chronic Passive Congestion The central
veins are red and the surrounding hepatic tissue
is pale tan-brown.
10
Liver Chronic Passive Congestion Slightly
visible centrilobar pattern
11
Liver Chronic Passive Congestion Accentuated
lobar pattern with a dark red stain surrounding
the central veins in the liver lobules (arrows)
12
Liver lobules Congestion and RBC accumulation in
the sinusoidal spaces around the central vein.
Note that the portal triads (arrows) are quite
normal and there is no evidence of congestion.
13
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.
14
Liver Chronic Passive Congestion Macrophages
distended with a brown pigment (arrow). These
resident macrophages (Kupffer cells) are part of
the reticuloendothelial system and normally line
the sinusoidal spaces in the liver where they
phagocytose the RBCs that pool, and eventually
die, in the central vein region.
15
Cut surface of a liver (left) with Chronic
Passive Congestion compared to the cut surface of
a nutmeg (right)
16
Heart Mural Thrombosis Arrow Well formed
thrombus tightly attached to the myocardium near
the apex of the left ventricle
17
Thrombis (1) attached to the Myocardium (2)
18
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 (arrows).
19
Border between the thrombus (1) and the
endocardium (2) In this region there is less
inflammation at the border zone.
20
Heart Mural Thrombosis This illustrates the
layered effect of the thrombus.
21
Heart Mural Thrombosis Note the pale region
which contains primary platelets (degranulated
platelets) with some fibrin (1), and the red
areas which contain RBCs, some leukocytes, and
fibrin (2).
22
Heart Mural Thrombosis 1 The pale regions
contain primary platelets (degranulated
platelets) with some fibrin. 2 The red areas
contain RBCs, some leukocytes, and fibrin.
23
Thrombosed Coronary Artery (arrows)
24
Coronary Artery Thrombosis The thrombus (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.
25
Coronary Artery Thrombosis Ruptured fibrous cap
(arrows) with hemorrhage into the atherosclerotic
plaque.
26
Coronary Artery Thrombosis Ruptured fibrous cap
(arrows) with hemorrhage into the atherosclerotic
plaque. Note the presence of cholesterol
crystals.
27
Coronary Artery Thrombosis Thrombus attached to
wall of vessel. There is early organization of
the thrombus (arrow).
28
Coronary Artery Thrombosis Thrombus attached to
the wall of the vessel. Note the early
organization with in-growth of fibroblasts and
small blood vessels from the wall of the artery
(arrows).
29
Coronary Artery A mural thrombus has undergone
reorganization. The mural thrombus has been
invaded by the in-growth of fibroblasts and small
blood vessels from the wall of the artery. The
thrombotic material has been phagocytosed and
removed by macrophages and is replaced by fibrous
connective tissue and blood vessels. This
reorganized thrombus still compromises the lumen
of the vessel.
30
Coronary Artery Thrombosis Adventitia (1) and
Media (2) contain inflammatory cells. The
recanalized portion of the vessel is composed of
fibrous connective tissue and contains numerous
small blood vessels. There is a small area of
hemorrhage (arrow) in the central portion of this
image.
31
Coronary Artery Thrombosis Adventitia (1) and
Media (2) contain inflammatory cells. The
recanalized portion of the vessel (3) is composed
of fibrous connective tissue and contains
numerous small blood vessels (arrows).
32
Coronary Artery Thrombosis Luminal surface of
re-canalized vessel Note the vessel lumen is
lined by endothelial cells (arrows).
33
Lung Thromboemboli in pulmonary arteries
34
Heart with main pulmonary artery opened Note the
thromboembolus filling the pulmonary artery
(arrows).
35
Leg muscle and veins Arrows Thrombus
36
Lung with large thrombus lodged at this branch
point in the pulmonary artery Note the hemorrhage
and congestion in the surrounding lung parenchyma.
37
Wall of the pulmonary artery (1) containing the
thromboembolus In this case the artery wall looks
normal. If this was a thrombus instead of a
thromboembolus, you would expect to see some
damage in the artery wall that would have
initiated the thrombus. Note the Lines of Zhan in
the thromboembolus (arrows).
38
Infarcted lung The tissue is congested and has a
very bland appearance due to coagulation necrosis
in the lung parenchyma. You can still see the
outlines of the alveoli and the cells that make
up the alveoli, but there is almost complete loss
of nuclei throughout this section.
39
Infarcted testis Cut surface (Note filled
with blood) Because of the anatomy of the blood
supply to the testis, torsion of the blood
vessels often leads to venous occlusion (due to
compression of thin walled veins) but not
arterial occlusion. Thus, blood can get in but
it cant get out. This leads to hypoxia and
eventually to hemorrhagic necrosis.
40
Opened abdomen at autopsy, demonstrating loops of
infarcted bowel (arrow) Vascular occlusion can
lead to ischemic necrosis of the bowel. In this
case, a section of bowel herniated through a
fibrous connective tissue band and was
strangulated, leading to ischemic necrosis.
41
Fibrous band between uterus and adjacent
tissue The fibrous scar tissue is probably left
over from a pervious surgery or an infection. A
loop of bowel herniated through the opening
produced by this fibrous band and became
incarcerated leading to the ischemic necrosis
seen in the previous image.
42
Lung Microabscesses due to septic
embolization Note the small 2-3 mm lesions
scattered throughout this lung tissue (arrows).
43
Myocardium with multiple embolic lesions
scattered throughout the left and right ventricles
44
Section of lung (left) and myocardium
(right) Both pieces of tissue have multiple
embolic lesions seen as blue staining areas with
massive infiltration of inflammatory cells
(arrows).
45
Focal lesions in the lung produced by septic
emboli Note these are clearly demarcated from the
relatively normal surrounding lung tissue.
46
Septic abscesses illustrating the colonies of
bacteria within necrotic cellular debris
(arrows) This is typical of an abscess.
47
Myocardium with Septic Abscesses (arrows)
48
Abscesses within the myocardium illustrating
colonies of bacteria as dark blue-staining
material (arrow)
49
Myocardial abscess stained with a special Gram
tissue stain to illustrate the colonies of
bacteria in this myocardial tissue (arrows)
50
Aorta opened lenghtwise with the luminal surface
visible Note the rough surface with ulcerations
and adherent thrombotic material. There is a
mild dilation (aneurysm) at the distal aorta just
at the bifurcation with an accumulation of
thrombus.
51
Lumen of aorta from previous image The rough,
ulcerated surface and thrombotic material can
easily be seen.
52
Kidney Several blood vessels can be identified at
the corticomedullary junction (arrows)
53
Arcurate arteries with a chronic embolus Note the
needle-shaped space (arrow) within the lumen of
this artery (arrow) which represents the space
occupied by the cholesterol crystal that was
dissolved away during histologic processing.
54
Atherosclerotic embolus Note the cholesterol
clefts (1) and thrombotic material (2) that
occlude this artery.
55
Mesenteric artery with atherosclerotic
embolus Again, note the cholesterol clefts and
thrombotic material that occlude this artery.