1. Skin: Neurofibromatosis Lab 5, Case 1

2. Neurofibromas Some lesions can be seen as subcutaneous swellings (arrow) and others form pedunculated masses. Most are hyperpigmented.

3. Subcutaneous neurofibroma (1) Note the increased pigmentation in the skin (2).

4. Neurofibroma (1) with overlying skin (2)

5. Neurofibroma demonstrating the loose pattern of elongated cells making up the tumor mass

6. Neurofibroma Shows more clearly the elongated cells (primarily Schwann cells) that make up this tumor

7. Cells in the neurofibroma

8. Kidney: Polycystic Kidney Disease Lab 5, Case 2

9. Note that both kidneys contain multiple large cysts.

10. One of the kidneys from this case next to a normal kidney, demonstrating how big these polycystic kidneys are compared to a normal kidney

11. Cut section from polycystic kidney Note that the renal parenchyma is almost completely replaced by cystic structures.

12. H & E stained section of polycystic kidney Note the large cystic structures (1), the few residual glomeruli (2), and the fibrous connective tissue throughout this section.

13. H & E stained section of polycystic kidney Again note the large cystic structures (arrows) and the fibrous connective tissue throughout this section.

14. 1: Edge of a large cyst In this section there are numerous tubules and dilated collecting ducts (2) that are filled with the same red proteinaceous material as the larger cysts.

15. Abnormal glomeruli (arrows) and some tubules

16. Liver from patient with polycystic kidney disease Multiple cysts can be seen on the surface of this liver (arrows).

17. Histologic appearance of liver cysts

18. These cystic structures are associated with the biliary tree.

19. Liver These cystic structures are lined by biliary epithelium.

20. Lung: α 1-Antitrypsin Deficiency Lab 5, Case 3

21. The rough friable material on the surface of the lung (arrows) is fibrinous exudate and fibrous tissue. This reaction on the surface is due to the recent surgery. The emphysematous change is not easily appreciated in this photograph.

22. Cut section of lungs The lung parenchyma is markedly hemorrhagic and consolidated. Again the hemorrhage makes it difficult to appreciate the emphysematous changes.

23. Bronchi and lungs Note the hemorrhage in the bronchi and lung parenchyma.

24. Hemorrhage present throughout the lung Note also the large air spaces; even though they are filled with blood, the emphysematous enlargement of the spaces is appreciable.

25. An area of lung without significant hemorrhage The enlarged, emphysematous spaces are easily appreciated.

26. Liver from this case The capsule is somewhat thickened and the surface is slightly roughened, though it is difficult to appreciate the nodularity of the liver.

27. Cut section of liver from this case In this view the liver looks smaller than normal, but there is a definite micronodular appearance.

28. Cut section of liver There is a definite micronodular appearance to the liver parenchyma.

29. H & E stained section of the liver There are increased numbers of inflammatory cells in the periportal region (arrow) and the central vein areas are pale.

30. Trichrome stained liver section There is bridging fibrosis (blue material) between portal regions.

31. Trichrome stained liver section This section demonstrates the fibrosis (blue material) and the fatty change (arrows).

32. PAS stained liver This demonstrates the PAS-positive granules of defective α 1-antitrypsin that accumulate in the Golgi of hepatocytes (arrows).

33. Liver: Hemochromatosis Lab 5, Case 4

34. Liver (1) and pancreas (2) from this case of hemochromatosis Note that both organs have a dark brown coloration.

35. Cut section of liver Note that the liver is dark brown. Although it is hard to appreciate in this photo, the tissue is also firm (cirrhotic).

36. Liver Note the nodularity of the tissue (arrows).

37. Nodules and the brown/black pigment within the liver parenchymal cells (arrows)

38. Liver Increased fibrosis in the periportal area (1) and the pigment accumulation (2)

39. Trichrome stain demonstrating the increased fibrous connective tissue in this liver. Note that the liver nodules (1) are surrounded by fibrous connective tissue (2).

40. Liver stained with Prussian blue, which reacts with iron to give the tissue a blue color

41. Liver stained with Prussian blue demonstrating the marked accumulation of iron within the parenchymal cells (1) and in the Kupffer cells in the periportal area (2).

42. Pancreas Note the brown discoloration

43. Pancreas It is difficult to appreciate at this magnification, but there is brown pigment in the pancreatic acinar cells. Note the islets of Langerhans (1).

44. Pancreas stained with Prussian blue Note the accumulation of iron in the parenchymal cells (1). There is also iron in the pancreatic islets (2).

45. Spleen: Gaucher Disease Lab 5, Case 5

46. This spleen is enlarged and the surface is finely granular.

47. Cut surface of spleen Note the fine granular appearance to the tissue.

48. Normal spleen (left) and spleen from this case (right) The loose appearance of the tissue in the Gaucher spleen is due to artifactual loss of tissue during histologic processing.

49. Spleen Very little if any white pulp visible in this picture.

50. Spleen Again there is no white pulp and the red pulp is filled with large eosinophilic cells.

51. Spleen At this power, it is easier to see the large eosinophilic cells.

52. Spleen Individual cells can be better appreciated.

53. Spleen At this higher power individual cells can be better appreciated and the fibrillar nature of the eosinophilic cytoplasmic material can be seen.

54. Gout Lab 5, Case 6

55. Index finger from patient with gout This finger has been sectioned longitudinally to demonstrate the distal interphalangeal joint. Note the white chalky material within and adjacent to the joint.

56. Elbow of patient from this case The subcutaneous nodules are (arrows) on this arm are tophi caused by gout.

57. Tophus removed from elbow of this patient Note the fibrous connective tissue (1) and the large foci containing urate crystals (2) surrounded by the intense chronic inflammatory reaction.

58. Higher magnification of previous image Collections of urate crystals (1) and the inflammatory cells at the edge of these foci (2)

59. Edge of the tophus Most of the urate crystals dissolve away during processing. The inflammatory cells at the edge of these foci are clearly visible (arrow).

60. Edge of the tophus The character of the intense chronic inflammatory cell reaction is evident and note the presence of giant cells within this inflammatory reaction (arrows).

61. Tophus that was fixed in alcohol before histologic processing The alcohol processing preserves the water soluble uric acid crystals within the tissue. Note the urate crystals visible (arrows). Also note the chronic inflammatory reaction in the background.

62. Tophus from another patient with gout The healed surgical incision and the size of the tophus indicate that this was a long-standing problem for this patient.

63. Kidney: Nodular Intercapillary Glomerulosclerosis Lab 5, Case 7

64. Kidneys from this case Note that there are multiple shrunken regions (old infarcts) (arrows) and the kidneys have a rough granular appearance on the surface, which is caused by multiple small infarcts of small vessels throughout the cortex.

65. Section of kidney extending from cortex (1) to the medulla (2)

66. Cortical region In this region there is ischemic obsolescence of glomeruli and one glomerulus with nodular glomerulosclerosis (1). Also note the thickened walls of blood vessels (2).

67. Two glomeruli with intercapillary glomerulosclerosis (arrows)

68. Glomerulus with nodular glomerulosclerosis (1) Also note the intertubular fibrosis and changes in the blood vessels (2).

69. Glomerulus with nodular glomerulosclerosis (arrows) These are the classic Kimmelstiel-Wilson lesions (“K-W lesions”) seen in diabetics with nodular glomerulosclerosis.

70. Kidney with focal exudative lesion in a glomerulus (arrow) and sclerosis, interstitial fibrosis, and congestion

71. Trisomy 21 Lab 5, Case 8

72. This is a pictomicrograph of cells obtained from amniocentesis that were stained using FISH. The cell in panel 1 was stained with markers specific for the X and Y chromosomes. The cell in panel 2 was stained with a marker specific for chromosome 18. The cell in the center was stained with markers for chromosomes 13 and 21. Note that there are three copies of chromosome 21.

73. These cells, obtained by amniocentesis, were cultured and then arrested in metaphase. Nuclei from these cells were isolated and stained to demonstrate the banding pattern of each chromosome. This pictograph shows a “chromosome spread.” Each chromosome is identified and lined up to give a karyotype (next slide).

74. Chromosomes from the chromosome spread are lined up to demonstrate the karyotype. In this case there are three copies of chromosome 21, just as noted in the FISH.

75. FISH is also useful in the diagnosis of other genetic disorders. This is an example of FISH staining on another patient using a probe specific for DiGeorge’s disease. The arrow shows that there is a deletion on chromosome 22, which is diagnostic for DiGeorge’s disease.

76. This is a karyotype of a patient with Klinefelter Syndrome (47, XXY).

77. This is a karyotype of a patient with Turner’s Syndrome (45, X).