Pathology of Cancer

Question 1

Why is it important to understand the?pathology of cancer?

Answer 1

It explains how cancers present clinically, such as consequences of a mass growing in a large bronchus, rectal bleeding, jaundice, haemoptysis, and respiratory disease.

Question 2

What are histopathological assessments important for?

Answer 2

They are important for diagnosis, prognosis, treatment, and additional ancillary tests like molecular testing.

Question 3

Define neoplasia.

Answer 3

A neoplasm is a mass of cells that have undergone an irreversible change from normality, proliferate in an uncoordinated manner, and are partially or completely independent of the factors which control normal cell growth.

Question 4

What does neoplasm literally mean?

Answer 4

It literally means ‘new growth’.

Question 5

Do neoplastic growths persist?

Answer 5

Yes, neoplastic growth persists even if the initiating stimulus is withdrawn, e.g., stopping smoking will not stop cancer growth.

Question 6

What is a commonly used synonym for neoplasm?

Answer 6

Tumour, which literally means ‘swelling’.

Question 7

Define cancer.

Answer 7

A malignant neoplasm.

Question 8

How can neoplasms be classified pathologically?

Answer 8

By behaviour (benign or malignant), histiogenesis (tissue of origin), histological subtyping, and functional classification.

Question 9

What do malignant neoplasms have the capacity for that benign ones don’t?

Answer 9

Local invasion into surrounding tissue and spread to distant sites to form secondary deposits (metastases).

Question 10

What is the term ‘cancer’ used to describe?

Answer 10

All types of malignant neoplasm.

Question 11

What is the typical appearance of a benign neoplasm?

Answer 11

Typically well circumscribed and does not invade locally, making it easier to resect.

Question 12

What is an example of a malignant neoplasm?

Answer 12

A squamous cell carcinoma derived from the squamous epithelium lining the oesophagus, displaying local invasion and lymph node metastases.

Question 13

What is staging of malignant neoplasms based on?

Answer 13

The extent of spread (local or distant).

Question 14

Which staging system is commonly used historically?

Answer 14

The TNM system, where T = tumour, N = nodes, M = metastasis.

Question 15

What type of neoplasms are derived from epithelial tissue?

Answer 15

Most malignant neoplasms, such as those from skin, lung, and gastrointestinal tract.

Question 16

What type of neoplasms are derived from mesenchymal tissues?

Answer 16

They account for many benign neoplasms (e.g., soft tissue lipoma) and if malignant, are termed sarcoma.

Question 17

What are haemato-lymphoid neoplasms?

Answer 17

Lymphoma (from lymph nodes) and leukaemia (if involving blood cells).

Question 18

What are examples of germ cell neoplasms?

Answer 18

Teratoma and seminoma.

Question 19

Define differentiation.

Answer 19

The degree to which a neoplasm histologically resembles its tissue of origin.

Question 20

Describe benign neoplasms differentiation.

Answer 20

They are always well-differentiated.

Question 21

Describe malignant neoplasms differentiation.

Answer 21

Differentiation is variable; they may be similar or very different.

Question 22

What is the term grading used for?

Answer 22

Grading describes the degree of differentiation, with implications for prognosis and treatment.

Question 23

What are anaplastic neoplasms?

Answer 23

Malignant tumours that are so poorly differentiated that it is impossible to determine their histiogenesis.

Question 24

Example of a well differentiated adenocarcinoma.

Answer 24

A well differentiated adenocarcinoma of the stomach resembles normal gastric mucosa but is malignant due to local invasion.

Question 25

Example of an anaplastic (undifferentiated) carcinoma.

Answer 25

An irregular mass blocking the lumen of the bronchus, with sheets of small cells that do not resemble normal bronchial tissue.

Question 26

What is further histological classification of neoplasms done by?

Answer 26

Specific histological features, such as the classification of glandular neoplasms.

Question 27

How are thyroid cancers classified?

Answer 27

According to their histological appearances into three main types: papillary, follicular, and anaplastic.

Question 28

What is functional classification?

Answer 28

Classification according to substances produced, such as endocrine neoplasms secreting hormones.

Question 29

What are teratomas?

Answer 29

Neoplasms derived from embryonic germ cells that can form representatives of all three germ cell layers.

Question 30

Where do embryonic tumours arise from?

Answer 30

Neoplastic transformation occurring in the developing organ, derived from multi-potential embryonic 'blast' cells.

Question 31

What are hamartomas?

Answer 31

Tumour-like malformations that are not genuine neoplasms.

Question 32

What are the comparisons between benign and malignant neoplasms?

Answer 32

Essential differences include growth rate, invasiveness, metastasis potential, differentiation, and prognosis.

Question 33

What is the gross appearance of a benign neoplasm in the colon?

Answer 33

A benign neoplasm in this site will be an adenoma.

Question 34

What is the malignant counterpart of a benign adenoma in the colon?

Answer 34

The malignant one is adenocarcinoma.

Question 35

What is the relationship between colonic adenocarcinomas and adenomas?

Answer 35

The majority of colonic adenocarcinomas arise from pre-existing adenomas.

Question 36

How does the size of a colonic neoplasm relate to malignant transformation?

Answer 36

The larger a colonic neoplasm, the more likely it is to have areas of malignant transformation.

Question 37

What are the microscopic features of normal/benign cells?

Answer 37

Cells are normal and organized.

Question 38

What are the microscopic features of malignant cells?

Answer 38

Cells vary in size, shape, and show loss of polarity.

Question 39

What is the effect of benign neoplasms on the host?

Answer 39

Benign neoplasms only cause problems by local mechanical pressure.

Question 40

What is an example of a benign neoplasm?

Answer 40

Uterine Leiomyomas (fibroids): Benign Neoplasm – Well Circumscribed & Well Differentiated.

Question 41

Where do uterine leiomyomas arise from?

Answer 41

They arise from smooth muscle in the wall of the uterus.

Question 42

What is an example of a malignant neoplasm?

Answer 42

Rectum Adenocarcinoma: Malignant Neoplasm – Irregular and Ulcerated, Moderately Differentiated.

Question 43

What are typical features of rectum adenocarcinoma?

Answer 43

Irregular outlines and centrally ulcerated.

Question 44

How can malignant glands be distinguished from normal rectal mucosa?

Answer 44

Malignant glands have enlarged nuclei that are not basally located, prominent nuclei, and several mitoses, while normal rectal mucosa has uniform small basally located nuclei.

Question 45

What are the features of anaplastic carcinoma?

Answer 45

Big nuclei, prominent nuclei, several mitoses.