1. Arrows: Areas of fresh myocardial infarction in the anterior portion of L Ventricle extending into the anterior portion of the intraventricular septum Note that the walls of the left and right ventricles are slightly thicker than normal

2. Left ventricular free wall extending from epicardium (1) to the endocardium (2). The area of infarction is darker red (hypereosinophilic area) along the subendocardium (3).

3. Directly beneath the endocardium is a pale area consisting of cardiac myocytes exhibiting vacuolar degeneration (1). The area of infarction is visible as a hypereosinophilic area (2) and there is a second zone of vacuolated myocytes (3) between the infarct and the normal myocardium (4).

4. 1: Area of infarction 2: An area of vacuolated myocytes adjacent to the infarcted myocytes 3: Normal cardiac muscle

5. 1: Endocardium 2: Area of subendocardial vacuolar degeneration 3: The area of infarction contains some RBCs

6. The border between the vacuolated subendocardial myocytes (1) and the infarcted myocytes (2)

7. 1: Normal Myocytes 2: Vacuolated Myocytes 3: Infarcted Myocytes

8. The surface of the kidney (left) shows marked nodularity and roughening and scarring from chronic hypertension. Arrow: Most recent infarct

9. Triangular shaped infarction with the base at the cortical surface (1) and the apex at the corticomedullary junction (2).

10. Sharply demarcated area of red discoloration extending from the capsule to the corticomedullary junction (arrow) Kidney

11. 1: Coagulative necrosis2: Normal tissue The necrotic tubules in this hemorrhagic, red infarct are hypereosinophilic. Compare the tubules on the right with the normal tubules seen on the left. Note the interstitial hemorrhage which is associated with vascular leakage within this necrotic region in this tissue.

12. 1: Barely identifiable glomerulus Retention of the tubular structure and cellular outlines. Although the cellular architecture is retained, there are no nuclei within the renal tubular cells. The nuclei visible are those of inflammatory cells.

13. Corticomedullary Junction Arrow: Blood vessel filled with thrombotic material. This vessel has occluded an end artery, resulting in ischemia and infarction.

14. Triangular shaped infarct. The shape is due to the blood flow distribution of the renal circulation. Apex (arrow) at the corticomedullary junction

15. Arrows: Abscesses Entire lung is consolidated Arrows: Areas of early abscess formation Note circumscribed whitish-tan lesions, which are filled with white blood cells

16. Arrows: Abscesses Note that the material inside the abscess have been expelled. Lung

17. Edge of the abscessLung 1: Loss of material from center of abscess 2: Loose necrotic material that has not been expelled. This material is made of inflammatory cells (primarily dead white blood cells) and necrotic lung tissue

18. Lung tissue containing large abscess The center of the abscess contains necrotic debris (1) and there is a rim of viable inflammatory cells (arrows) surrounding this abscess.

19. Small abscess with necrotic center Lung

20. Center of abscess containing neutrophils and necrotic debris

21. Arrows: Small abscess full of inflammatory cells, primarily neutrophils 1: Bacterial colony in center of abscess

22. Intestines and omentum Arrows: Small, white nodules on the surface of the omental and mesenteric fat tissue

23. White nodules in the pancreas and the adjacent mesenteric fat tissue

24. 1: Fat tissue surrounding the pancreas 2: Blue areas in fat adjacent to the pancreas Arrows: Rim of inflammatory cells

25. Arrows: Fat necrosis 1: Inflammation 2: Peripancreatic Fat Tissue

26. Blue discoloration in the fat tissue in the interlobular spaces (1) of the pancreas

27. 1: Small area of fat necrosis The appearance of the pancreatic tissue in this area is somewhat disrupted due to autolysis but there is some premortum necrosis as well

28. Fat necrosis involving the fat cells in the interlobular spaces (arrow) of the pancreas Note the purple to blue staining of the calcium deposits within the fat cells

29. Fat necrosis in the interlobular spaces of the pancreas Note the blue-staining calcium deposits (arrows) within the fat cells The clear areas represent the artifact caused by “washing out” of fat from cells during tissue processing for histology

30. Calcification (arrows) seen in fat necrosis involving the interlobular spaces of the pancreas

31. Disseminated tuberculosis The numerous small white nodules scattered throughout the lung tissue represent individual tuberculosis granulomas. In addition, note the dark areas throughout the lung which represent deposits of anthracotic pigment.

32. Arrows: White granulomas (Miliary tuberculosis) Dark areas of anthracosis are also prominent.

33. Hilar lymph nodes from a patient with disseminated Tb The white, cheesy-appearing nodules (arrows) give rise to the descriptive terms caseous necrosis. The black pigment is anthracotic pigment that has drained from the lungs.

34. Lung of a patient with chronic history of respiratory disease Arrows: Eosinophilic nodules Other areas of the lung are relatively normal. Several bronchi and large vessels can be seen. Pleural surface at left

35. Arrows: Eosinophilic nodules Surrounding inflammatory response in remaining normal lung tissue

36. Single nodule with amorphous eosinophilic center and accumulation of cells around the outer edge. This is typical of a granuloma in which there is a necrotic center (1) and a rim of lymphocytes, macrophages, and occasional multinucleated giant cells around the periphery.

37. Granuloma with the amorphous eosinophilic material representing caesation necrosis (1), giant cells near the center (2), and inflammatory cells around the periphery.

38. Langhans-type multinucleated giant cell, characteristic of Tb granulomas (arrow). Note the horseshoe shape of the nuclei of the giant cell. The majority of cells in the upper left portion of this section are macrophages which provide the major cellular component in the granuloma. Note the smaller number of blue-staining cells in the peripheral portions of this granuloma to the left of which are lymphocytes.

39. Normal area of prostate Arrow: Corpora amylacea, small hyaine masses of degenerated cells and inspissated secretions

40. Prostatic Epithelium Arrows: Cells with pyknotic fragmented nuclei Note that the cytoplasm is condensed and hypereosinophilic

41. Prostatic Epithelium Demonstrates in situ immunohistochemical technique used to identify DNA fragments characteristic of apoptotic nuclei. TUNEL is used to identify apoptotic cells (arrows) in histology samples.

42. Prostatic epithelium with TUNEL staining Note the apoptotic cells (brown nuclei) in the epithelium as well as floating freely