Presentation on theme: "Appendix removed from patient with acute appendicitis."— Presentation transcript:
1Appendix removed from patient with acute appendicitis. Note the rough, shaggy material (arrows) on the surface due to deposition of fibrin and inflammatory cells.
2Appendix with acute inflammatory response Normal Appendix Note the abundant blue-staining lymphoid tissue beneath the mucosal layer and the absence of blue-staining cells in the submucosal layer in the normal appendix. Compare this with the extensive distribution of cells in the appendix with acute appendicitis. The blue color is due to the presence of many inflammatory cells, although at this low power the individual cells cannot be specifically identified.
3Appendix with acute inflammation Note there are only remnants of mucosal tissue identifiable along the luminal borderThere is an extensive infiltration of leukocytes.Notice that the surface is rough and has deposits of fibrin.
41: Serosal surface of the appendix 2: Submucosal center with remnants of a lymphoid nodule. Surrounding this lymphoid nodule are masses of leukocytes which should not be present in a normal appendix.
5Arrow: A small area of normal mucosal epithelium. This area is surrounded by areas of ulceration with an inflammatory infiltrate of lymphocytes and neutrophils.
6Arrows: Loss of normal mucosal epithelium and the inflammatory infiltrate The principal inflammatory cell in this case of acute appendicitis is the neutrophil.
7Open abdominal cavity of a patient with acute appendicitis There has been rupture of the appendix with spillage of the intestinal contents into the abdominal cavity. This spillage resulted in an “acute abdomen” and widespread inflammation throughout the abdominal cavity.Note the roughened surface of the mesenteric tissue (arrow) due to the deposition of fibrin over much of the surface.
8Another example of peritonitis Note the fibrinosuppurative exudate covering the abdominal organs
9Acute lobar pneumoniaThe left lung is affected with pneumonia (arrows). It has whitish discoloration and appears swollen compared to the more pink-staining normal lung (lower right and left had portions of the photo).
10Cut section of lung with acute lobar pneumonia Note the whitish discoloration of the tissue in the upper lobe (arrows) compared to the normal collapsed and pink-staining lung lobe in the left-hand portion of the photo. The white discoloration is due to infiltration of leukocytes, primarily neutrophils. Note that only one lobe of the lung is involved in this patient.
11Right lung of the same patient This lung shows complete consolidation with a marked infiltration of neutrophils throughout the tissue, giving a whitish discoloration. This is an advanced case of lobar pneumonia with extensive necrosis which obviously did not resolve, thus resulting in the death of the patient.Note the extensive black pigment due to anthracosis.
121: Markedly thickened pleura, indicating an inflammatory process that has been ongoing for days 2: A small, wedge-shaped segment of normal lung which is somewhat compressed due to artifact3: A large, wedge-shaped segment of lung with lobar pneumonia, which appears very dense due to extensive cellular infiltrate4: A greatly thickened pleural space between these two lobes due to deposition of fibrinous exudate
13Interpleural space between the two lobes 1: Thickened pleura with extensive fibrin deposits2: The affected lung lobe3: Extensive fibrin deposits in the interlobar space
14Junction of the pleura (1) with the pneumonic lung parenchyma Arrows: outline of alveolar structuresThe mass of cells infiltrating this tissue consist almost exclusively of neutrophils (PMNs).
15Junction of pleura (1) with parenchyma Note the alveoli (2) filled with PMNs, alveolar macrophages, and fibrinThe dark red-stained material (3) is fibrin in the pleura.There are RBCs trapped in the fibrinous pleuritis as well.
16Alveoli filled with exudate The alveolar walls (arrows) are barely visible. The alveoli are filled with PMNs, fibrin, and edema fluid. This is a severe acute inflammatory response but the structure of the alveoli remains intact. This tissue is able, with proper treatment, to completely resolve this inflammatory response. Since there has not been necrosis, this lung could completely recover normal function (resolution).
17Lung with multiple abscesses Arrows: individual lung abscesses
181: Multiple focal lesions 2: Lesion with a pale center, indicating loss of parenchymal tissue. This is typical of abscess formation in the lung and represents liquefaction necrosis.This is bronchopneumonia since the distribution is along the bronchi and the terminal airway distribution throughout the lung. Note that there are some areas that appear completely normal, having a normal-staining appearance. Other areas are much darker (3), indicating a heavy cellular infiltrate.
191: Wall of the abscess2: Liquefaction necrosis in the center of the abscess3: The remaining lung tissue has extensive infiltration into the alveoli.The abscess has destroyed a portion of the lung, but other areas of the lung where the structure has been retained could recover normal function.
20Lung with bronchopneumonia Note that the alveolar structure of this tissue, which is in the region of a terminal bronchiole (1), has been retained despite the massive infiltration of inflammatory cells. These inflammatory cells are primarily neutrophils.
211: A terminal bronchiole in which the mucosal lining has been almost completely destroyed There is extensive neutrophilic infiltration throughout this tissue.
22Central portion of an abscess Note the absence of any parenchymal tissue due to extensive neutrophilic infiltration with liquefaction necrosis of the parenchymal tissue. Masses of leukocytes (primarily neutrophils), fluid, and necrotic debris within an abscess form what is referred to as “purulent material” or “pus”. The blue-staining mass in the center of this abscess (arrow) represents colonies of bacteria.
23Lymph NodeNote the rather pale pink color of the tissue with dark-staining cells found in only a few scattered areas. These darker cells represent the original lymphocytes cells of this lymphoid organ.
24Lymph NodeIllustrates a paucity of lymphocytes as well as numerous, pale-staining nodules (arrows) throughout the tissue
25The small nodules (arrows) seen in the previous image Close examination reveals they are composed of macrophages (epithelioid macrophages). These small granulomas form multiple series of reaction centers throughout the lymph node. Note the remaining lymphocytes surrounding the granulomas.
26Single granulomaArrows: Individual macrophages that make up the bulk of the tissueIn this case, there is an absence of necrosis in the center.
271: Multinucleated giant cell 2: In the center of this foreign-body containing giant cell there is a small asteroid body. No functional significance.
29Note that the lesion appears solid and has a whitish coloration, indicating considerable fibrous connective tissue.This is a healed granuloma due to primary Tb in the lung. There are smaller focal lesions adjacent to the major mass. In addition, notice the extensive anthracosis.
30Multiple large nodules (1) with pale eosinophilic centers surrounded by a rim of blue-staining tissue. In addition to the large nodules, there are several smaller nodules (2) throughout the slide.
31Tb GranulomaCentral core of caseation necrosis (1) encircled by a rim of epithelioid macrophages and lymphocytes (2). Langhans type multinucleated cells are present, but difficult to see (3).
32Granuloma1: Necrotic core : Epithelioid macrophages 3: Langhans’ type giant cellsNote the small lymphocytes, characterized by their distinctly blue-staining nuclei. Other cells include fibroblasts and occasional neutrophils.
34Lung and PleuraArrows: HemorrhagesArrows: Small focal lesions throughout parenchyma
35These granulomas surround blood vessels. Note RBC in lumen (arrow).
36Taken under partially polarized light to demonstrate the birefringent particles within the granulomas (1)These granulomas are adjacent to blood vessels (2).Fully polarized lightShows numerous birefringent particles
37Acute Fibrinous Pericarditis The pericardium on this heart has been reflected back (arrows). The surface of the heart is rough due to the deposition of fibrin on the epicardial surface of the heart and on the inner surface of the pericardium.
38Heart with pericardium removed Most of epicardial surface is covered with fibrinous deposits. There are a few glistening areas of exposed normal epicardial tissue.
39Arrows: Dark-red staining fibrin deposits on the inner surface The pericardium is much thicker than normal and there are numerous inflammatory cells within the pericardial tissue.
40Arrows: Fronds of fibrin extending from the surface of the pericardium
41Fibrin (red amorphous material) on the surface of the pericardium (1) Note the reactive mesothelial cells on the surface of the pericardium (arrows) and the inflammatory cells within the pericardium.
42Stomach containing an ulcer Note the folded pink gastric mucosa that extends up to the edge of the ulcer (arrows)
43The ulcer after it has been transected 1: Edge of the mucosa2: The thick fatty tissue which makes up the base of the ulcer (3)
44Transected ulcer1: Normal gastric epithelial cells of the mucosa2: Crater of the ulcer; note the absence of cells
45Margin of the ulcer1: Intact epithelium2: Ulcerated region with no epitheliumThere are numerous inflammatory cells.
46Base of the ulcer1: Fibrinopurulent membrane overlying the ulcerated surface2: The ulcerated surface contains granulation tissue and inflammatory cells.
47Arrows: Ulcer Base; note the lack of epithelium 1: Exhuberant inflammatory response consisting primarily of fibrin, adherent gastric secretions, and PMNsThe surface of the ulcer bed is covered with this fibrinopurulent exudate.
48Plump, activated fibroblasts and endothelial cells (arrows) within the granulation tissue that makes up the base of the ulcer.There are inflammatory cells (primarily lymphocytes) in this region as well.
49Serosal SurfaceBaseHealing reaction at the ulcer baseNote the fibrous connective tissue within the wall of the stomach and the layer of inflammatory exudate on the surface of the ulcer (arrow)
51Serosal surface (1) from a section of stomach near ulcer Note that the inflammatory reaction extends out to the serosa.
52Ulcer SurfaceBlue: Fibrous connective tissue scar formation in this lesionThere is a layer of inflammatory cells and RBCs on the surface of the ulcer.
53Brain with two areas of infarction Arrows: Areas of infarction
54Edge of infarctNote the loss of brain parenchyma (arrows)
55Edge of infarctNote the numerous inflammatory cells in the parenchyma and adjacent to the remaining brain tissue (arrows).
56Enlargement of previous image Arrows: The inflammatory cells are primarily macrophages and microglia which have phagocytosed the dead brain tissue.
57Brain tissue adjacent to the are of infarction There are numerous activated gemistocytic astrocytes (arrows).
58Edge of the infarctThe macrophages that are full of dead brain tissue (“glitter cells”) are at the top of the image (arrows) and the brain parenchyma containing gemistocytic astrocytes is at the bottom.
60Edge of infarctNote the glitter cells, gemistocytic astrocytes, and some hemosiderin-laden macrophages (arrows).
61Old healed infarctNote the meninges overlying the infarcted area (arrow).
62Old healed infarct with the meninges containing blood vessels (arrow) overlying the infarcted region
631: Layer of surviving myocardial tissue along the epicardium 2: Blue line representing accumulation of inflammatory cells at the border of the infarct3: Thrombotic material adherent to the endocardial surface
641: Viable tissue along the epicardium 2: Blue line of inflammatory cells3: Infarcted myocardium
651: Normal tissue2: Accumulation of inflammatory cells3: Edge of the infarcted tissue
661: Accumulation of inflammatory cells 2: Infarcted tissueNote that intact cells can be seen in the infarct, but they do not have nuclei.
67Edge of infarct Heart tissue Arrows: Hypereosinophilic cells
68Mural thrombus adherent to the endocardial surface (arrows)
69Lines of ZhanPale areas (1) represent platelets with some fibrin and the darker lines (2) represent RBCs and leukocytes enmeshed in fibrin strands.