Lecture 27

Question 1

What is a neoplasm?

Answer 1

Refers the persistence of tumors, even after the inciting stimulus is gone, results from genetic alterations that are passed down to the progeny of the tumor cells. These genetic changes allow excessive and unregulated proliferation that becomes autonomous (independent of physiologic growth stimuli)

Question 2

Name the components of the neoplasm that is shown below:

Answer 2

Red = the neoplastic cells themselves no longer responding to cellular signalling mechanisms

Light blue arrows = neoplastic stroma supporting the neoplasm structurally

Orange = the immune cells themselves

Green = red blood vessel formation

Question 3

Name the type of neoplastic cell that is shown below and provide an example of a neoplasm that may have caused this:

Answer 3

Round cells - all immune cells do this

Question 4

Name the type of neoplastic cell that is shown below and provide an example of a cell that might do this:

Answer 4

Mesenchymal cells: spindle cells (cells like fibroblasts and myocytes)

Question 5

Name the type of neoplastic cell that is shown below and provide an example of a type of cell that would do this:

Answer 5

Epithelial cells: skin and epithelial cells, glandular cells - these can look squamous, polygymal, pumps, lumps, islands and trabeculae

Question 6

What types of cells are generally more prone to becoming neoplastic?

Answer 6

1. Permanent cardiac myocytes are much less likely to become neoplastic
2. Labile and stable cells are more susceptible - permanent cells are not really dividing as much by comparison

Question 7

Can some non-neoplastic changes develop into neoplasia?

Answer 7

Yes

Question 8

What are some methods beyond histology that can be used to assess whether a tissue is neoplastic?

Answer 8

1. Radiology
2. Use PCR - polyclonal is less likely to be a neoplasm, whereas monoclonal is more likely to be a neoplasm

Question 9

How do round cells differ from epithelial cells on cytology?

Answer 9

Round cells: these can look like epithelial cells (one key difference is that they do not clump together they will be individualised

Epithelial cells: they hold onto each other unlike round cells - epithelial cells like to form together to form clusters or bands

Question 10

How do mesenchymal cells appear histologically?

Answer 10

They typically appear as being spindle shaped with long wispy projections

Question 11

Name the origins of the neoplasms in the image below:

Answer 11

1. Lymphocytes
2. Mast cells
3. Melanocytes
4. Plasma cells
5. Macrophages

Question 12

Name the origin of the mesenchymal cells below:

Answer 12

1. Fibroblasts as they are producing collagen
2. Producing bone and hence a tumour of bone
3. Neoplasm of cartiladge
4. Blood vessels - probably a neoplasm of enodthelial cells
5. Looks like fat - benign tumour of adipocytes or lipocytes (lipoma)
6. Less well differentiated neoplasm of fat cells (liposarcoma)

Question 13

Name the neoplasms that are shown in the image below:

Answer 13

1. Hepatocytes
2. Gastric mucosal epithelial cells or mucosal epithelium or any part of alimentry tract
3. Epidermal Keratinocytes
4. Renal tubular epithelial cells
5. Mammary glandular epithelium

Question 14

Contrast the two terms benign and malignant:

Answer 14

Benign: no invasion, well demarcated, no metastasis, low mitotic rate, often smaller, ulcers + necrosis & haemmorage is rare, diseases are due to space occuping lesions or tumour products, resemble the tissue of origin, mild anisocytosis and anisokaryosis, minimal nuclear atypia

Malignant: locally invase, poorly demarcated, metastasis common, rapid growth rate and high mitotic rate, often larger, often ulcerate & contains necrosis and haemmorrhage, disease due to metastasis, poorly differentiated (loss of resemblance), marked anisocytosis (variation in cell size) and anisokaryosis (variation in nuclear size), nuclear atypia (abnormal shapes and multiple nuclei)

Question 15

How are epithelial neoplasms named?

Answer 15

Benign - end is -oma or papilloma if papillary

Malignant - called a carcinoma or an adenocarcinoma (glandular)

Question 16

How are neoplasms of mesenchymal cells named?

Answer 16

Benign - ends in -oma

Malignent - end in -sarcoma

Question 17

How are round neoplasms nomenclaturised?

Answer 17

No consistent nomenclature exists for them