Neoplasia

Question 1

What are the basic tumor classification?

Answer 1

Mesenchymal
Epithelial
Haematopoietic and lymphoid

Question 2

What are mesenchymal cells?

Answer 2

connective tissue, cartilage, bone

Question 3

What are epithelial cells?

Answer 3

epidermis, glandular surfaces and functional part of organs

Question 4

What are haematopoietic cells?

Answer 4

bone marrow cells which make blood cells; lymphocytes, plasma cells and lymphoid organs

Question 5

What are examples of mesenchymal cells?

Answer 5

• fibroblasts
• endothelial cells
• chondrocytes

Question 6

What are examples of epithelial cells?

Answer 6

• urothelium
• apocrine glands
• squamous cells

Question 7

What are examples of haemopoetic and lymphoid cells?

Answer 7

• lymphocytes
• mast cells
• plasma cells

Question 8

What are the general rules of mesenchymal tumors?

Answer 8

• benign, ends in ‘oma’
• malignant, ends in ‘sarcoma’

Question 9

What are the general rules of epithelial tumors?

Answer 9

non glandular
- [cell type] papillioma if benign
- [cell type] carcinoma if malignant

glandular
- squamous cell papilloma if benign
- squamous cell carcinoma if malignant

Question 10

What are the gross features of a malignant tumor?

Answer 10

• Rate of growth
• Tissue invasion?
• Metastatic spread?

Question 11

What are the features of a benign tumor upon palpation?

Answer 11

Benign tumors on palpation are well demarcated under the skin, is able to move and is not infiltrating other tissues

Question 12

What are the types of metastatic spread?

Answer 12

• Direct seeding - in cavities
• Haematogenous - blood vessels
• Lymphatic - lymphatic vessels

Question 13

What microscopic features of cells are looked at when determining malignancy of a tumor?

Answer 13

benign tumours look like the origin cells while malignant lose the normal cell architecture

Question 14

What is anaplasia?

Answer 14

loss of normal cell architecture

Question 15

What is Pleomorphism

Answer 15

Variation in the size & shape of cells and/or nuclei

Question 16

What is Anisocytosis?

Answer 16

Greater than normal variation in cell size

Question 17

What is Anisokaryosis?

Answer 17

Greater than normal variation in nuclear size

Question 18

What are nuclear changes associated with malignancy?

Answer 18

-Increased nuclear size
-Increased nuclear number
-Coarse & clumped chromatin & hyperchromasia
-Increased / abnormal mitotic figures

Question 19

What are the microscopic features of benign tumors?

Answer 19

• Cohesive
• may be encaspulated
• Not invasive

Question 20

What are the microscopic features of malignant tumors?

Answer 20

• Invasion
• Infiltration and destruction of surrounding tissues

Question 21

What is the origin and features of spindle shaped tumors?

Answer 21

mesenchymal
- Elongated, fusiform
- often in streaming bundles
- may have swirling patters

Question 22

What is the origin and features of epithelioid tumors?

Answer 22

Epithelial
- Columnar, cuboidal polygonal, squamous or rounded shapes
- adhesive junctions between cells
- may form cords, nests or lobules
- May form acinar and tubular structures - Circular shape

Question 23

What is the origin and features of Round tumors?

Answer 23

lymphocytes, plasma, mast cells and histocytes

• Discrete (individual) round or oval shaped
• can be arranged in sheets
• may be loosely or densely packed

Question 24

What are direct effects on the host?

Answer 24

• Space occupying and compressive effects
  
  • example - spinal cord or bile duct
• Obstructive effects
  
  • example - block intestine - Intestinal adenocarcinoma
• Ulceration and tissue destruction
• Haemorrhage

Question 25

What are indirect effects on the host?

Answer 25

- Alteration to structure or function of tissues distant from the tumour site - Can involve bone, RBCs, blood calcium and nerves

Question 26

What are paraneoplastic syndromes?

Answer 26

Indirect effects that occur when there's an alteration in structure / function of cells, tissue or organs distant from tumour site

Question 27

What tissues are involved with paraneoplastic syndrome?

Answer 27

cross reactivity between neoplastic tissue and normal tissue

Question 28

how does paraneoplastic syndrome occur?

Answer 28

immune mediated disease as tumour antigen expressed is same as host

Question 29

How can humoral hypercalcaemia of malignancy (psuedohyperparathyroidism) be caused?

Answer 29

- Tumour releases PTHrP (Parathyroid hormone related peptide) which can act as a parathyroid hormone - bind to receptors causing hypercalcaemia

Question 30

What tumors can cause humoral hypercalcaemia?

Answer 30

Lymphomas or Anal sac apocrine gland carcinoma (dogs)

Question 31

What are some general features of benign tumours?

Answer 31

-Slow growth rate -Non invasive -Solid margins -If pinched, able to move with subcut. tissue over underlying deeper tissue -Well differentiated -May be encapsulated -Cohesive (cells stick together & create one discrete mass)

Question 32

What are some general features of malignant tumours?

Answer 32

-Fast growth rate -Invasive -Difficult to appreciate margins -Fixed position -Metastatic spread -Poorly / undifferentiated (anaplastic) -Cellular & nuclear pleomorphism (+ anisocytosis & anisokaryosis) -Nuclear changes