Pathology Neoplasia Short And Long Essay Question And Answers

Neoplasia Important Notes

1. Exfoliative cytology or Pap smear

It involves the study of cells that spontaneously shed off from epithelial surfaces into body cavities or body fluids
It is based on the principle that malignant cells are incohesive and loose
Thus they shed off into the lumen
The cells are obtained by scraping, brushing or washing mucosal surfaces

2. Metastasis

It is used to distinguish benign and malignant tumours
Malignant tumours can metastasize
Carcinomas metastasize through lymphatics while sarcomas through blood vessels

3. Oncogenic viruses

These are viruses which induce carcinogenesis
They may contain either DNA or RNA

Examples:

Neoplasia Oncogenic viruses

Neoplasia Long Essays

Question 1. Define neoplasia. Give the difference between benign and malignant tumours. Add a note on the paraneoplastic syndrome.
Answer:

Neoplasia Definition:

Neoplasia is defined as a mass of tissue formed as a result of the abnormal, excessive, uncoordinated, autonomous and purposeless proliferation of cells even after cessation of stimulus for growth which causes it.

Differences between benign and malignant tumours:

Neoplasia Differences Between Benign and Malignant Tumours.

Paraneoplastic Syndrome:

Para neoplastic syndromes are a group of conditions developing in patients with advanced cancer which are neither explained by direct and distant spread of the turn-over nor by the usual hormone elaboration by the tissue of origin of the tumour.

They occur in 10% -15% of patients with cancer.
Various clinical syndromes included in INS are.
- Endocrine syndrome.
  - Hypercalcemia
  - Cushing’s syndrome
  - Polycythemia
  - Flypoglycacmia.

Read And Learn More: Pathology Question And Answers

- Neuromyopathic syndromes
- Haematologic and vascular syndrome
- Gastrointestinal syndrome
- Renal syndrome
- Cutaneous syndromes
- Amyloidosis.

Question 2. Define neoplasia. Classify tumours. Discuss the mode of spread of malignant tumours.
Answer:

Classification of Tumours:

Neoplasia Classification Of Tumours

Spread of Tumours: It is by 2 ways.

1. Local invasion/direct spread:

Benign tumours:
- Form encapsulated/circumscribed masses
- These that expand and push aside the surrounding normal tissues without actually invading, in- filtrating/metastasising.
Malignant tumours: They also enlarge by expansion.
- These tumours invade via the route of least resistance
- Often cancers extend through tissue spaces, via lymphatics, blood vessels, and perineural spaces and may penetrate bone.
- More commonly, tumours invade thin-walled capillaries and veins than thick-walled arteries.

2. Metastasis/Distant spread:

Metastasis is defined as the spread of tumours by inva¬sion in such a way that discontinuous secondary tumour mass/masses are formed at the site of lodgement.
Benign tumours do not metastasise while all malignant tumours with a few exceptions like gliomas of the CNS and basal cell carcinoma of skin can me¬tastasis.

Routes of Metasis:

1. Lymphatic spread: In general, carcinomas metastasize by lymphatic route

Involvement of lymph nodes by malignant cells may be of two forms.

Neoplasia Involvement Of Lymph Nodes By Mailgnant Cells

2. Haemategenous spread:

Sarcomas spread through hematogenous spread
The common site for blood-borne metastasis are
- Lung,
- Breast,
- Thyroid,
- kidney,
- Liberate and
- Ovary.
Spread:

Neoplasia Haemategenous Spread

Various other routes:

Neoplasia Various Other Routes

Question 3. Define tumour. Write briefly about carcino¬gens. Describe gross and microscopic features of squamous cell carcinoma.
Answer:

Tumour: Tumour is defined as a mass of tissue formed as a result of abnormal, excessive, uncoordinated, autonomous and purposeless proliferation of cells
Carcinogens: The agents which can induce tumours are called carcinogens

Types of Carcinogens:

Neoplasia Types Of Carcinogens

Squamous Cell Carcinoma Features:

Age: common in older individuals
Sites involved
- Lower lip
- Lateral tongue
- The floor of the mouth
- Soft palate
- Gingiva
- Alveolar ridge
- Buccal mucosa
Presentation
- Initially asymptomatic lesion
- Resembles leukoplakia
- Appears as a white or red nodule or fissure over the mucosa
- The advanced lesion appears as rapidly enlarging exo-phytic growth or ulcer or tumour-like mass
- The ulcer has persistent induration around the periph¬ery with elevated and everted margins
- May predispose candidal infections
- May be a secondary infected

Squamous Cell Carcinoma Morphology:

Gross appearance:

It appears as nodular or lucrative growth
Shows fungating and polypoid mass without ulceration
Margin- elevated and indurated

Cut section

It shows grey-white endophytic as well as exophytic tumours

Microscopic appearance

It is characterised by malignant cells
These cells show variable degrees of differentiation
Cells invade through the basement membrane into the dermis

Arrangement

Cells are arranged in concentric layers called epithelial pearls
They contain keratin material in the centre of the cell masses
Cells are separated by lymphocytes

Question 4. Discuss about injury caused by ionizing radiation.
Answer:

Ionizing radiation like X-rays, alpha, beta and gamma rays can cause cancer
Cancer caused by them are
- Cancer of
  - Thyroid
  - Skin
  - Breast
  - Ovary
  - Uterus
  - Lung
  - Myeloma
  - Salivary glands
  - Leukaemia

Ionizing radiation Mechanism:

It causes DNA damage by one of the following mechanism
- Direct damage to cellular DNA
- Dislodges ions from water and other molecules of the cell and result in the formation of highly reactive free radicals that causes damage

Effects of Radiation:

Chromosomal breakage
Translocation
Point mutation

Factors effecting it

Type of radiation
Dose
Dose rate
Frequency
Host factors
- Age
- Individual susceptibility
- Immune competence
- Hormonal influences
- Type of cells irradiated

Question 5. Define carcinogenesis. Discuss in detail the chemical carcinogenesis.
Answer:

Definition

Carcinogenesis means the mechanism of induction of tumours
Agents that induce tumours are called carcinogens

Chemical carcinogenesis:

Chemical carcinogens have highly reactive electrophile groups that directly damage DNA leading to mutations and eventually cancer.
Depending upon the mode of action, they are classified as:
1. Initiator carcinogens.
2. Promoter carcinogens

1. Initiator carcinogens: They can initiate the process of neoplastic transformation.

Direct-acting carcinogens: They do not require metabolic activation.
- Alkylating agents: Anticancer drugs (Cyclophosphamide, busulfan, melphalan, nitrosourea),
- β-propionolactone and episodes.
Indirect-acting agents (Procarcinogens): They require metabolic activation.
- Polycyclic and heterocyclic aromatic hydrocarbons: Benzathracenes, benzopyrene.
- Aromaticamaines, amides and azo dyesmaphthylamine ([3-naphthylamine), Ben-zidine and azo dyes like 2 – acctylaminofluorene, dimethyl amino azo benzene (butter yellow)
- Naturally occurring products: Chemical derived from plants and microbial sources i.e., aflatoxin Bl,
- Others: Nitrosamines/Nitrosamides in gastric carcinoma, insecticides, fungicides etc.

2. Promoter carcinogens:

It promotes further clonal proliferation and expression of initiated cells
Examples Phorbol esters, phenols, hormones like estrogen

Question 6. Define neoplasia. Classify oncogenic viruses and explain the role of viruses in carcinogenesis.
Answer:

Neoplasia Definition:

Neoplasia is defined as a mass of tissue formed as a result of abnormal, excessive, uncoordinated, autono¬mous and purposeless proliferation of cells even after cessation of stimulus for growth which causes it

Oncogenic Viruses:

They are associated with neoplasms
Based on nucleic acid content, oncogenic viruses are divided into 2 groups:

DNA viruses
RNA viruses

Role Of Virus In Carcinogenesis:

Neoplasia Mode Of DNA virus

Neoplasia Mode Of RNA virus

Neoplasia Short Essays

Question 1. Characteristics of malignancy
Answer:

1. Rate of growth:

Malignant tumour cells have increased mitotic rates and slower death rates i.e., cancer cells do not follow normal control in the cell cycle and are immortal.
Also, the rate of growth is directly proportional to the degree of differentiation.

2. Clinical and gross features:

Clinically, malignant tumours grow rapidly, ulcerate on the surface, invade locally into deep tissues, may spread to distant sites, produce weight loss, anorexia and anaemia.
Grossly, irregular in shape, poorly circumscribed and extending into adjacent tissues secondary changes like haemorrhage, infarction and ulceration are seen more often.

3. Microscopic features:

Malignant tumours have a poor resemblance to origin.
Basal polarity is lost
Pleomorphism is present hyperchromatism and abnormal mitotic figures are seen.
The nucleocytoplasmic ratio is increased anisonucleo- sis is generally present
Tumour giant cells are present with nuclear atypia.
The function may be retained/lost/abnormal.

4. Local invasion:

Tumours invade via routes of least resistance eventually most cancers recognize no anatomic boundaries.
Cancers extend through tissue space, permeate lymphatics, blood vessels, and perineural spaces and may penetrate the bone by going through nutrient foramina.

5. Metastasis/Distance spread:

Lymphatic spread – In general carcinomas metastasize by the lymphatic route.
Hematogenous spread – Common route for sarcomas.
Spread along body cavities and natural passages – Routes are trans coelom, epithelial lined surfaces, CSF, and implantation.

Question 3. Staging of tumours
Answer:

Staging of cancer is determined by surgical exploration or imaging and is based on the size, local and regional lymph node spread and distant metastasis.
Staging is a system to determine the prognosis and choice of treatment of malignant cancer.
Important systems of staging which currently in use are as follows:
- TNM system (T-primary tumour, N-regional lymph node involvement, M-metastases]
- ATC (American Joint Committee) System.
Both systems take into account the following criteria;
- Size of the primary tumour
- Nodal involvement
- Metastasis

TNM Staging: For each of the 3 components T, N and M, numbers are added to indicate the extent of involvement as under:

T₀ to T₄: In sites to the largest and most expensive primary tumour
N₀ to N₃: NO nodal involvement to widespread lymph node involvement.
M₀ to M₂: NO metastasis to disseminated haematoge- nous metastasis.

AJC system: Cancers are divided into stages 0 to 4 and take into account all the 3 components i.e., size, nodal spread and distant metastasis.

Neoplasia Short Question And Answers

Question 1. Oncogenes
Answer:

Mutant versions of proto-oncogenes that function autonomously without a requirement for normal growth-promoting signals are known as oncogenes.
A normal gene/proto-oncogene is converted / acti¬vated to an oncogene by.
- Change in the structure of the gene
- Change in regulations of gene expression.
Oncogenes are activated by.
- Point mutation and deletion
- Chromosomal translocation
- Gene amplification.

Question 2. Oncogenic viruses
(or)
Virus-related human tumours and examples.
Answer:

Oncogenic viruses are associated with neoplasms.
Based on nucleic acid content, oncogenic viruses are divided into 2 groups.
- DNA viruses
- KNA viruses.

DNA oncogenic viruses: DNA oncogenic viruses have direct access to the host cell nucleus and are incorporated to the genome of the host cell DNA.

Classified into 5 groups.

Pap ova virus: Responsible for skin warts (squamous cell papillomae and invasive cervical cancer.
Herpes virus: Epstein- ban virus (EBV] Burkitt’s lymphoma and human herpes virus 8 kaposi’s sar¬coma.
Adenovirus: Causes respiratory tract infections and pharyngitis
Poxvines: They cause moluscum contagiosum
Hepadna virus: Hepatitis B virus.

Question 3. Lab diagnosis of cancer
Answer:

Neoplasia Lab Diagnosis Of Cancer

Question 4. Burkitt’s lymphoma
Answer:

It is a distinctive type of B-cell lymphoma caused by Epstein-Barr virus [EBV] infection.
3 sub-groups of Burkitt’s lymphoma are:

African endemic
Sporadic
Immunodeficiency associated.

Burkitt’s lymphoma Etiology – EBV infection and immune suppression.

Burkitt’s Lymphoma Features:

The disease affects children and adolescents
Involves extranodal sites, particularly the jaw, gas- tro intestinal tract and gonads.

Histological appearances: Tightly packed lymphoblasts interspersed with phagocytic macrophages which impart a starry-sky appearance in histological sections.

Question 5. Etiology of oral cancer
Answer:

Neoplasia Etiology Of Oral Cancer

Question 6. Ionizing radiation
Answer: Ionizing radiation like X-rays, alpha, beta and gamma rays can cause cancer