neoplasia

Question 1

What is Cancer?

Answer 1

Cancer is a disease caused by normal cells changing so that they grow in an uncontrolled way, invade surrounding tissue, and travel to other parts of the body (metastasis).

Question 2

How is Cancer caused?

Answer 2

The origin of cancer, known as its aetiology, involves the accumulation of genetic alterations (e.g., mutations, deletions, translocations) and epigenetic changes (e.g., promoter methylation) in cells. These changes can be inherited or caused by external factors such as smoking, diet, UV irradiation, pollutants, viruses, or natural cell processes. These alterations result in abnormal (neoplastic) cell growth and tumor formation.

Question 3

What does the term “tumour” refer to?

Answer 3

The term “tumour” is now commonly used as a synonym for “neoplasm” and refers to a swelling or new growth of abnormal cells.

Question 4

What is neoplasia?

Answer 4

Neoplasia refers to the “new growth” of abnormal cells.

Question 5

What are the two types of tumours?

Answer 5

Tumours are classified as either benign or malignant. Benign tumours are not harmful or life-threatening, while malignant tumours are life-threatening and considered “evil in nature.”

Question 6

What is another term for cancer?

Answer 6

Cancer is synonymous with “malignant neoplasm” or “malignant tumour.” The term “cancer” has its roots in Latin, where it referred to a “crab” or “creeping ulcer.” In Greek mythology, “Karkinos” was a giant crab, and the swollen veins surrounding tumours were said to resemble the limbs of a crab.

Question 7

How are tumours classified?

Answer 7

Tumours are classified based on their behaviour (benign or malignant) and histogenesis (cell or tissue of origin). Accurate classification of individual tumours is essential for accurate diagnosis, prognosis, and treatment.

Question 8

What are the differences between benign and malignant tumours in terms of growth rate?

Answer 8

Benign tumours have a slow growth rate, while malignant tumours have a relatively rapid growth rate.

Question 9

What is the difference in mitotic figures between benign and malignant tumours?

Answer 9

Mitotic figures, which are dividing cells, are rare in benign tumours but common in malignant tumours.

Question 10

How do benign and malignant tumours differ in histological resemblance to normal tissue?

Answer 10

Benign tumours often have a good histological resemblance to normal tissue, while malignant tumours have a variable resemblance and often poor resemblance to normal tissue.

Question 11

Do benign tumours invade surrounding tissues?

Answer 11

No, benign tumours do not invade surrounding tissues.

Question 12

What about metastasis? Do benign tumours metastasize?

Answer 12

Benign tumours never metastasize, while malignant tumours frequently metastasize.

Question 13

How do benign and malignant tumours differ in terms of their border?

Answer 13

Benign tumours typically have well-defined or encapsulated borders, whereas malignant tumours may have poorly defined or irregular borders.

Question 14

Is necrosis (cell death) common in benign tumours?

Answer 14

No, necrosis is rare in benign tumours but common in malignant tumours.

Question 15

What is the characteristic growth pattern of benign tumours on epithelial or mucosal surfaces?

Answer 15

When a benign tumour arises on an epithelial or mucosal surface, it grows away from the surface because it cannot invade. This often creates an exophytic lesion that grows outwards, forming either a pedunculated (stalked) or sessile (sitting on the surface) polyp.

Question 16

What are some clinical problems that benign tumours can cause?

Answer 16

Although benign tumours are confined to their site of origin, they may cause clinical problems due to pressure on adjacent tissues, obstruction of fluid flow, hormone production, transformation into a malignant neoplasm, or anxiety in the patient.

Question 17

How do malignant tumours behave on epithelial or mucosal surfaces?

Answer 17

Malignant tumours on epithelial or mucosal surfaces may initially form a protrusion, but eventually, they invade the underlying tissue, giving rise to an endophytic tumour that grows inwards. Ulceration is common in these cases.

Question 18

How do malignant tumours behave in solid organs?

Answer 18

In solid organs, malignant tumours tend to have irregular margins, often with tongues of neoplastic tissue penetrating adjacent normal structures. They often show central necrosis due to inadequate vascular perfusion.

Question 19

What are some of the issues associated with malignant tumours?

Answer 19

Malignant tumours are associated with significant morbidity and mortality due to pressure on and destruction of adjacent tissue, formation of secondary tumours (metastases), blood loss from ulcerated surfaces, obstruction of flow in certain organs, production of hormones leading to systemic effects, paraneoplastic effects causing weight loss and debility, as well as anxiety and pain.

Question 20

What are the characteristics of borderline tumours?

Answer 20

Borderline tumours exhibit some features associated with malignancy, such as irregular architecture, nuclear stratification and pleomorphism, and increased mitotic activity. However, they lack the most important criterion of invasion. Their biological behavior, as determined by histology, is intermediate between that of clearly benign and overtly malignant tumours.

Question 21

What is histogenetic classification of tumours based on?

Answer 21

Histogenetic classification of tumours is based on the tissue or cell of origin. It is determined through histopathological examination, which involves the microscopic study of biological tissues.

Question 22

What is histology and how does it relate to gross anatomy?

Answer 22

Histology is the microscopic study of biological tissues. It is the microscopic counterpart to gross anatomy, which focuses on the study of organs and structures visible to the naked eye.

Question 23

What is histopathology?

Answer 23

Histopathology is the microscopic study of diseased tissue. It involves examining tissue samples to identify any pathological changes or abnormalities.

Question 24

How does histogenetic classification of tumours categorize them?

Answer 24

Histogenetic classification categorizes tumours based on the specific cell or tissue of origin, which is determined through histopathological examination. The tumour type is specified by the cell or tissue of origin and is incorporated into the tumour’s name. Major categories of origin include epithelial cells (forming carcinomas), connective tissues or mesenchymal tissues (forming sarcomas), haematopoietic system (forming leukaemias), and lymphatic system (forming lymphomas).

Question 25

What suffix is commonly used for neoplasms?

Answer 25

Neoplasms commonly have the suffix “-oma”.

Question 26

What are the terms used for benign epithelial tumours and their subtypes?

Answer 26

Benign epithelial tumours are referred to as papillomas or adenomas. A papilloma is a benign tumour of nonglandular or nonsecretory epithelium, while an adenoma is a benign tumour of glandular or secretory epithelium.

Question 27

What is the term used for malignant epithelial tumours?

Answer 27

Malignant epithelial tumours are called carcinomas.

Question 28

How are benign connective/other mesenchymal tissue tumours named?

Answer 28

Benign connective/other mesenchymal tissue tumours are named using a prefix that denotes the specific cell of origin.

Question 29

What is the term used for malignant connective/other mesenchymal tissue tumours?

Answer 29

Malignant connective/other mesenchymal tissue tumours are referred to as sarcomas.

Question 30

What is tumour grading?

Answer 30

Tumour grading is a classification system that describes how closely the tumour resembles its cell or tissue of origin. It is determined by histological examination, assessing key features such as mitotic activity, cellular and nuclear features (size and shape), and degree of resemblance to normal tissue (differentiation).

Question 31

What is the purpose of tumour grading?

Answer 31

Tumour grading is clinically useful as it correlates strongly with patient survival (prognosis) and helps in making treatment decisions.

Question 32

What is tumour staging?

Answer 32

Tumour staging is a process that describes the anatomical extent of the spread of the tumour. It provides information about the size of the tumour and whether it has spread to nearby lymph nodes or distant organs.

Question 33

How do tumour grading systems differ?

Answer 33

Tumour grading systems differ depending on the type of cancer. There are numerical grading systems (e.g., grades 1, 2, 3) and description-based grading systems (e.g., low/medium/high grade or well/moderately/poorly differentiated).

Question 34

What does a low grade/well-differentiated tumour indicate?

Answer 34

A low grade/well-differentiated tumour indicates that the cells generally resemble the normal cells from which they are derived. These tumours are well differentiated, with normal tissue organization, and they grow slowly with a low mitotic index.

Question 35

What does a medium grade/moderately differentiated tumour indicate?

Answer 35

A medium grade/moderately differentiated tumour indicates that the cells may exhibit some loss of differentiation. The cells show abnormalities in shape and nuclei, and the tumour grows more rapidly than low-grade tumours.

Question 36

What does a high grade/poorly differentiated tumour indicate?

Answer 36

A high grade/poorly differentiated tumour indicates poorly differentiated tissue. The cells have abnormal shape and nuclear shape, and the tumour grows rapidly with a high mitotic index.

Question 37

What does tumour staging describe?

Answer 37

Tumour staging describes the anatomical extent of the spread of the tumour. It answers the question, “How far has this thing spread?”

Question 38

How is tumour staging determined?

Answer 38

Tumour staging is determined through a combination of histopathological examination of the tumour and clinical and radiological assessment of the patient. Imaging techniques are often used to aid in the staging process.

Question 39

What is the TNM system?

Answer 39

The TNM system is one of the most commonly used staging systems. It stands for:

T (Tumour): Describes the size and extent of the primary tumour.
N (Nodes): Indicates the involvement of regional lymph nodes.
M (Metastasis): Represents the presence or absence of distant metastasis.

Question 40

What is the significance of tumour staging?

Answer 40

Different stages of tumours have different prognoses and may require different types of treatment. Staging helps in determining the appropriate treatment approach and provides information about the expected outcome for the patient.