MoD Neoplasia 1

Question 1

Define neoplasm

Answer 1

An abnormal growth of cells that persists after the initial stimulus is removed
For malignant neoplasms: AND invades surrounding tissue with the potential to spread to distant sites

Question 2

Define tumour

Answer 2

A clinically detectable lump or swelling

Question 3

Define cancer

Answer 3

Any malignant neoplasm

Question 4

Define metastasis

Answer 4

A malignant neoplasm that has spread from its primary site to a non-contiguous secondary site

Question 5

Define dysplasia

Answer 5

A pre-neoplastic alteration in which cells show disordered tissue organisation. (It is not neoplastic because its reversible)

Question 6

Whats the difference between benign and malignant tumours?

Answer 6

Benign neoplasms are confined to their site of origin whereas malignant neoplasms have the potential to metastasise.

Question 7

How do benign and malignant neoplasms differ macroscopically?

Answer 7

Benign neoplasms grow in a confined area so have a pushing outer margin, they feel round and mobile.
Malignant neoplasms have an irregular margin and may show areas of necrosis (grow faster than the blood supply) and ulceration (break in the epithelium), so they feel bumpy and immobile.

Question 8

Define anaplasia

Answer 8

Cells are poorly differentiated and have no resemblance to any tissue type

Question 9

How to benign and malignant neoplasms differ microscopically? and how is this related to their grading?

Answer 9

Benign neoplasms have cells that are well differentiated so closely resemble the parent tissue.
Malignant neoplasms range from well to poorly differentiated.

Grade 1 - well differentiated, high survival rate
Grade 2 - moderately differentiated, moderate survival
Grade 3 - poorly differentiated, low survival rate

Question 10

How to cells appear microscopically with worsening differentiation?

Answer 10

Increased nuclear size and nuclear to cytoplasmic ratio
Increased nucleus staining (HYPERCHROMASIA)
More mitotic figures
Increased variation in size and shape of cells and nuclei (PLEOMORPHISM)

Question 11

Whats the difference between invasive and in-situ malignancy?

Answer 11

Carcinoma in-situ does not invade the basement membrane whereas invasive carcinoma does. Invasive has a poorer prognosis

Question 12

Discuss the clonality of neoplasms, and how we know they are monoclonal

Answer 12

Cells are monoclonal if they all originate from a single cell. We know that neoplasms are malignant through study of the X linked gene for glucose-6 phosphate dehydrogenase (G6PD) in tumour tissue. The gene has several alleles.

In female embryogenesis one allele is randomly inactivated in each cell (LYONISATION). In heterozygous women normal tissues will be a patchwork of the two different alleles whereas neoplastic tissues only express the one allele.

Question 13

What are photo-oncogenes?

Answer 13

Porto-Oncogenes are normal genes that can become abnormally activated to form oncogenes that favour neoplasm formation.
Oncogenes inactive tumour supressor genes.

Question 14

What causes neoplasia?

Answer 14

Accumulated mutations in somatic cells.
The mutations are called initiators (mutagenic agents) and promotors cause cell proliferation.
Initiators need lots of promotion to cause cancer.

Main initiators are chemicals, infections and radiation. Mutations can also be inherited (may result in neoplasm at a young age).

Question 15

Define progression

Answer 15

An accumulation of mutations in a monoclonal cell population

Question 16

What are the endings for the different types of neoplasms?

Answer 16

Benign neoplasms end in -oma

Malignant neoplasms end in -carcinoma if they are epithelial (90%) or -sarcoma if they are stromal

Question 17

Describe the different names of benign epithelial neoplasms

Answer 17

Benign stratified squamous neoplasms are called squamous papilloma’s (polyps with finger like projections)

Benign transitional neoplasms are called transitional cell papillomas

Benign glandular neoplasms are called adenomas

Question 18

Describe the different names of malignant epithelial neoplasms

Answer 18

Malignant epithelial neoplasms are called carcinomas

Malignant glandular neoplasms are called adenocarcinomas

Question 19

How are lymphoid and haematopoietic cancers named?

Answer 19

ALL regarded as malignant
Neoplasms of lymphoid tissue are called lymphomas
Haematopoietic cancers and calles leukaemias

Question 20

How are germ cell neoplasms named?

Answer 20

Testis
Malignant teratoma
Seminoma (malignant)

Ovary
Benign teratoma (also called dermoid cyst)

Question 21

What are malignant neoplasms of glial cells called?

note this is an exception!

Answer 21

Malignant glioma

ends in -oma but isn’t benign