1. Thyroid: Adenoma
Lab 7, Case 1

2. Thyroid Nodule
Note that the mass is well circumscribed and there is a sharp line of demarcation between the mass and the adjacent thyroid tissue (arrows).

3. High-power view of the border between the tumor mass and adjacent thyroid tissue
Note that the mass has compressed the adjacent normal thyroid tissue (arrow). Also note the different morphology between the adenoma (very cellular, dense follicles, little or no colloid) and the adjacent normal thyroid (larger follicles, colloid).

4. Adenoma Thyroid
Note the compression of the adjacent normal thyroid and the difference in morphology between the adenoma and the thryoid.

5. Densely packed follicular pattern in the adenoma (left) and the larger colloid-filled follicles of the normal thyroid on the right
An area of compressed thyroid is present adjacent to the adenoma (arrow).

6. Note that the follicular architecture is well developed and more or less uniform throughout this section of the adenoma.

7. Relatively normal cellular architecture of this follicular adenoma

8. Breast: Fibroadenoma
Lab 7, Case 2

9. Three ovoid, well-circumscribed nodules surrounded by fibroadipose tissue

10. Higher magnification of one of the three nodules
At this power, the nodule seems to be composed of a solid parenchyma with small glandular spaces. The adjacent breast parenchyma consists mostly of fat.

11. Fibroadenoma
Dense stroma of the tumor surrounding the irregularly shaped ducts
The adjacent fibrofatty tissue containing breast ducts and lobules has been compressed by the tumor.

12. Compressed connective tissue (arrow) between two nodules of dense fibrous tissue and ducts

13. Fibroadenoma
Ducts embedded in connective tissue

14. Fibroadenoma
Dense stroma of the tumor surrounding the irregularly shaped duct
The ducts are lined by two cell layers, one of cuboidal, two columnar cells (inner layer), and an outer layer of flattened cells with hyperchromatic nuclei (myoepithelial cells)

15. Fibroadenoma
Irregularly shaped ducts lined by two cell layers of cells, as previously described

16. Lips: Squamous Cell Carcinoma
Lab 7, Case 3

17. Pre-op photo of patient with an ulcerated lesion on his lip (arrow)
The area for surgical excision is outlined in black. Also note that the lip is somewhat thickened.

18. Squamous Cell Carcinoma of the Lip
1: Focal Ulceration
2: Tumor infiltration at the vermilion border

19. Large area of ulceration (arrow) with underlying congestion and hemorrhage
The area of ulceration is adjacent to an area of tumor infiltration.

20. Well-differentiated Squamous Cell Carcinoma and the inflammatory cell infiltration

21. Squamous Cell Carcinoma and inflammatory cells

22. Well-differentiated Squamous Cell Carcinoma
Note the intracytoplamic keratinization which gives the cells a glassy appearance. The focal accumulations of keratinized cells are called keratin pearls (arrows).

23. Poorly differentiated area of tumor
Note the spindle-shaped cells and the irregular pattern of growth.

24. Section of muscle from the lip biopsy
Note that the squamous cell carcinoma has infiltrated into the muscle tissue. There are also inflammatory cells within this area of tumor infiltration.

25. Esophagus: Squamous Cell Carcinoma
Lab 7, Case 4

26. Luminal surface of esophagus
1: Area of constriction (protrudes into lumen)
2: Central area of ulceration

27. Cross-section through esophagus at area of constriction
Shows extensive infiltration of the esophageal wall with squamous cell carcinoma (arrows)

28. Normal epithelium undergoing transition to carcinoma (arrows)

29. Invasive squamous cell carcinoma
Tongues and islands of tumor cells exhibit areas of central necrosis (arrow).

30. Bands of tumor cells invading into the adjacent tissues (arrows)

31. Bands of tumor cells (arrows) extending between the muscle bundles

32. Tumor cells that have invaded the adjacent muscle tissue

33. Colon: Adenocarcinoma
Lab 7, Case 5

34. Adenoma from the surgical specimen
Note the large, ulcerated, fungating annular (encircling) carcinoma (1) with areas of hemorrhage (2). Also note the adenomatous polyps (3).

35. Closer view of previous image demonstrating the raised, annular carcinoma (arrows)

36. Transition between normal mucosa on the left and carcinoma which is invading the wall of the bowel (arrow)

37. Transition between the normal (1) and the neoplastic (2) epithelium

38. Tumor cells invading the underlying muscularis

39. Tumor cells forming glands

40. Tumor cells forming glands

41. Ulcerated adenocarcinoma (arrows) at the rectosigmoid junction

42. Distal colon
Note the annular tumor that severely compromises the lumen of the colon. There is dilation of the colon proximal to the tumor.

43. Lung and Liver: Metastatic Adenocarcinoma
Lab 7, Case 6

44. Multiple, variably-sized pale/white-tan nodules scattered throughout the liver

45. Multiple, variably-sized pale/white-tan nodules scattered throughout the lung

46. Section of liver (left) and lung (right) containing tumor nodules (arrows)

47. Interface between the tumor (top) and normal liver parenchyma (bottom)

48. Tumor cells (arrows) have infiltrated into the liver parenchyma

49. Tumor cells forming glands (arrows)

50. Tumor nodule in the lung
The tumor cells are infiltrating into the lung parenchyma (1). There is a large area of necrosis in the center of the tumor (2).

51. Edge of the tumor nodule in the lung
The tumor cells are infiltrating into the lung parenchyma (1). Even at this power, you can see the glandular formation of this adenocarcinoma. There is a large area of necrosis in the center of the tumor (2).

52. Edge of the tumor nodule in the lung
The tumor cells are growing in a glandular pattern. The area of necrosis is evident at the right side of the image.

53. Breast: Infiltrating Ductal Carcinoma
Lab 7, Case 7

54. Surgical specimen of breast with infiltrating duct carcinoma
Note the tumor tissue under the area of the nipple. The tumor infiltrates in an irregular fashion into the breast parenchyma. Note the nipple retraction caused by this neoplasm.

55. Sections of normal breast (lower) and breast tissue with infiltrating duct carcinoma (upper)
Note the increased cellularity (increased blue staining due to the increased number of nuclei) in the tumor tissue.

56. Section of breast with small groups of carcinoma cells throughout the breast tissue and invading through the dermis

57. Abundant groups of tumor cells dissecting through the breast parenchyma
Tumor infiltration (infiltrating duct cell carcinoma)

58. Cellular and nuclear features of the tumor cells
The large epithelial cells form glands and are medium-sized with a moderate amount of cytoplasm, vesicular nuclei, and nucleoli.

59. Breast tissue with abundant fibrous tissue throughout the tumor (desmoplasia, scirrhous carcinoma)

60. Periphery of tumor
Bands of tumor cells infiltrating into the fat tissue

61. Growth pattern of the tumor
The tumor consists of malignant duct-lining cells growing in cords, solid cell nests, tubules, and glands. The cytologic detail of tumor cells varies from small cells with moderately hyperchromatic, regular nuclei to large cells with large, irregular, hyperchromatic nuclei.

62. Skin: Malignant Melanoma
Lab 7, Case 8

63. Skin with melanoma
Note the black pigment, multiple satellite nodules, and focal ulceration. Some of the satellite nodules affect the nipple.

64. Lymph nodes almost entirely replaced with black pigment (melanin)

65. This lymph node has a capsule (1) and some remaining lymphocytes (2) but the remainder of the node is replaced by tumor cells.

66. Remaining portion of lymph node (arrow)
The rest of the lymph node is invaded by a neoplasm composed of cells with lighter eosinophilic cytoplasm and pigment

67. Abundant extracellular melanin (arrows) surrounding the tumor cells
This section of neoplasm shows the numerous cells with abundant cytoplasm and brown pigment within the cytoplasm of some of these cells.

68. Abundant extracellular melanin (brown pigment) surrounding the tumor cells

69. Main tumor mass with the cells growing as poorly formed nests and sheets of cells
There is little if any pigment in this section.

70. Main tumor mass
The individual melanoma cells contain large nuclei with irregular contours having chromatin clumped at the periphery of the nuclear membrane and prominent red (eosinophilic) nucleoli.

71. Lung: Bronchogenic Carcinoma
Lab 7, Case 9

72. Bronchogenic Carcinoma
The large tumor mass can be seen adjacent to the bronchus (1). Note that the epithelium surface of the bronchus is rough and irregular (2). The first branch off of the right main stem bronchus is partially occluded by the thickened mucosa and submucosa (3).

73. Normal mucosa (1) with transition to carcinoma (2)
Note the bronchial cartilage (3) and the invasion of tumor through the entire wall of the bronchus with tumor extending to the serosal surface (4).

74. Bronchus
1: Ulcerated mucosal surface
2: The submucosa is completely filled with tumor down to the cartilage

75. Bronchus with ulcerated mucosal surface on the right and tumor underneath

76. Mucosal surface (right) with an area of hemorrhage (arrow) and underlying tumor (left)

77. Area of invasion with compression of fibrous stroma and focal necrosis

78. Cytologic detail of tumor
1: Area of necrosis
2: A more differentiated area with keratin pearl formation

79. Tumor with central area of necrosis (arrow)

80. Cytologic detail of less-differentiated area of neoplasm with cellular anaplasia

81. Ileocecal Valve: Carcinoid
Lab 7, Case 10

82. Surgical specimen
Eosinophilic and basophilic areas delineating areas of tumor infiltration

83. Arrows: Nests of tumor cells

84. Tumor growth pattern: Cells form discrete islands, trabeculae, and glands

85. The tumor cells are monotonously similar with scant, pink, granular cytoplasm and a round-to-oval stippled nucleus. As in most carcinoid tumors, there is minimal variation in cell and nuclear size, and mitoses are infrequent or absent.

86. Subcutaneous masses in cecum
Note that the mucosa (1) is mostly normal and the tumor cells are in the submucosa (2).

87. Higher power of previous image
Intact mucosa (right) and the submucosal carcinoid tumor

88. Subcutaneous mass in cecum
The mucosa is normal and the tumor cells are in the submucosa.

89. 1: Intact mucosa
2: A gland
3: Submucosal carcinoid tumor cells

90. Cecum containing tumor stained to demonstrate the secretory granules in these tumor cells (brown-colored stain)
The blue color is the mucin in the glands just under the mucosal surface.

91. Higher power view of previous image
Brown: Carcinoid tumor cells
Blue: Glands

92. Section from previous images stained with silver to delineate carcinoid tumor cells

93. Femur: Osteosarcoma
Lab 7, Case 11

94. Tumor in distal femur

95. Surgical specimen with tissue dissected away to demonstrate the tumor mass

96. Cut section of distal femur containing the tumor
The periosteal involvement is evident (arrows).

97. Decalcified section of this tumor
Note the blue color (cell nuclei stain blue) of much of this section indicating the increased cellularity of the tumor.

98. Decalcified section of this tumor
Areas of osteoid (1) and cellular areas (2)

99. Decalcified histologic section showing the cellularity of the tumor

100. Note that the cells are fusiform and they grow in sheets.

101. Demonstrates growth pattern and cellular morphology

102. Tumor cell morphology and the periosteum (arrow)

103. Fusiform morphology of the tumor cells
Note the marked variablilty in size and staining intensity of the nuclei.

104. Anaplastic cell morphology

105. Anaplastic cell morphology

106. Anaplastic cell morphology and multiple mitotic figures (arrows)