WEEK 3: General Pathology of Neoplasia

Question 1

What is a neoplasm?

Answer 1

“A neoplasm is an abnormal mass of tissue, the
growth of which is uncoordinated with that of
normal tissues, and that persists in the same
excessive manner after the cessation of the
stimulus which evoked the change’’.

Question 2

What is neoplasia?

Answer 2

An alternative OPERATIONAL definition of
neoplasia is “a growth disorder characterized by
genetic alterations that lead to loss of the normal
control mechanisms that regulate cell growth,
morphogenesis and differentiation.

Question 3

Outline characteristics of neoplasia.

Answer 3

 Abnormal tissue mass arise from tissue with
proliferative capacity
 Rapid and uncoordinated growth, irreversible
 Growth persists after cessation of the
stimulus
 Varying degree of differentiation
 Arise from genetic mutation.

Question 4

Define the following terms:
1. Proliferation
2. Differentiation
3. Anaplasia

Answer 4

 Proliferation: cell division to replace old cells or
provide additional cells when needed.

 Differentiation: The degree to which tissue
resemble their origin both in structure and
function

 Anaplasia: Lack of differentiation, loss of
structural and functional characteristics of
normal tissue

Question 5

Define the following terms:

1.Neoplasia
2.Tumor
3.Cancer
4.Oncology

Answer 5

 Neoplasia-new growth

 Tumor: An abnormal growth of cells or tissues.

 Cancer-common term for malignant neoplasm

 Oncology: The branch of medicine that deals with
cancer, including study of their development,
diagnosis, treatment, and prevention

Question 6

Outline the importance of neoplasia classification.

Answer 6

To aid in diagnosis.
To aid in treatment
To determine prognosis
To facilitate epidemiological analysis

Question 7

There are 2 central and complementary methods of tumor classification.

Outline.

Answer 7

1. Behavioral classification of tumors
   2.Histogenetic

Question 8

State the 2 behavioral classification.

Answer 8

*Benign
*Malignant

Question 9

Compare benign and malignant tumor.

Answer 9

BENIGN TUMOR
Slow growing
 Usually resemble tissue of origin
 Usually have a well circumscribed or encapsulated
 Nuclear morphology is usually normal.
 Necrosis is rare.
 Few mitoses
 Ulceration is rare.
 Never invade.
 Never metastasizes.

MALIGNANT TUMOR
 Relatively rapid growth rate
 Usually does not resemble tissue of origin.
 usually not well circumscribed or invade the
encapsulated.
 Nuclear morphology is usually abnormal.
 Necrosis is common.
 Many mitoses
 Often ulcerates.
 invade the surrounding tissue.
 metastasizes to distant sites.

Question 10

What is histogenesis?

How are tumors classified by histogenesis?

Answer 10

Histogenesis refers to the presumed cell of origin of a tumor.

 Tumors from a specific histological tissue often have microscopic features similar to that tissue.

 Thus, tumors arising in squamous epithelia have a squamous pattern and tumors arising from the
glandular epithelium of the gastro-intestinal tract
similarly have features resembling this epithelium.

 The degree of resemblance of a tumor to its
presumed tissue of origin allows tumors to be
GRADED.
 This is important since it correlates with PROGNOSIS.

Question 11

Describe the following prefixes for nomenclature of neoplasms.
1.ADENO:
2.PAPPILO
3.LIPO
4.OSTEO
5.CHONDRO
6.ANGIO
7.RHABDO
8.LEIOMYO
9.MENINGO
10.GLIO
11.FIBRO

Answer 11

ADENO: Glandular epithelium
PAPPILO: Non-glandular epithelium
LIPO: Fat
OSTEO: Bone
CHONDRO: Cartilage
ANGIO: Blood vessel
RHADBO: Skeletal muscle
LEIOMYO: Smooth muscle
MENINGO: Meninges
GLIO: Glial cells
FIBRO: Fibrous tissue

Question 12

Describe the following suffixes for nomenclature of neoplasms.
1.OMA
2.CARCINOMA
3.SARCOMA
4.AEMIA

Answer 12

OMA: Benign or malignant tumor
CARCINOMA: Epithelial malignancy
SARCOMA: Connective tissue malignancy
AEMIA: Bone marrow derived cells malignancy

Question 13

Outline the 2 main groups of epithelial benign tumors.

The 2 terms __________ and __________are incomplete without a specification of the specific epithelium from which the tumor derives.

Give examples of ways of on how complete names are written.

Answer 13

Two groups are recognized: -

 Adenoma: benign tumor of glandular epithelium
 Papilloma’s: benign tumor of non-glandular
epithelium

The terms adenoma and papilloma are incomplete without a specification of the specific epithelium from which the tumor derives.

 For example, transitional cell papilloma, squamous cell papilloma, rectal adenoma, bile duct adenoma

Question 14

Describe how to name malignant neoplasms of the epithelium.

Answer 14

 These are always carcinomas.

 As with benign epithelial tumors the use of a
qualifying term to denote the specific epithelium
of origin is essential.

 For example, adeno-carcinoma specifies a
malignant epithelial tumor arising from glandular
epithelium.

 This needs to be further qualified by the organ of
origin.

 Therefore, adenocarcinoma of the colon is a
malignant epithelial tumor arising from the
glandular epithelium of the colon.

Question 15

Name the malignant tumors of the following epithelium.

 Liver cells
 Transitional epithelium
 Renal cells epithelium
 Trophoblastic epithelium
 Bronchial epithelium
 Mammary epithelium
 Squamous epithelium
 Melanocytes

Answer 15

 Liver cells -Hepatocellular carcinoma
 Trasitional epithelium-Transitional cell carcinoma
 Renal cells epithelium-Renal cell carcinoma
 Trophoblastic epithelium-Choriocarcinona
 Bronchial epithelium-Brochogenic carcinoma
 Mammary epithelium-Breast carcinoma
 Squamous Epithelium-Squamous cell carcinoma
 Melanocytes-Melanocarcinoma(melanoma)

Question 16

Carcinomas can be further categorized by their
degree of differentiation or their resemblance to
the normal epithelium from which they are
derived.
 A well differentiated adenocarcinoma resembles
the ______________ and tends to have a better
_____________than a poorly differentiated adenocarcinoma which has less resemblance to the _______________.

 An anaplastic carcinoma is a malignant _____________with no morphological differentiation (and has a very poor prognosis).

Answer 16

Carcinomas can be further categorized by their
degree of differentiation or their resemblance to
the normal epithelium from which they are
derived.

 A well differentiated adenocarcinoma resembles
the normal epithelium and tends to have a better
prognosis than a poorly differentiated adenocarcinoma which has less resemblance to the
normal epithelium.

 An anaplastic carcinoma is a malignant epithelial
tumor with no morphological differentiation (and
has a very poor prognosis)

Question 17

How did the word cancer come about?

Answer 17

Cancer, the Latin word for crab

The malignant tumor growth pattern deep vertically resembles the shape of a crab.

Question 18

Name the benign and malignant tumor for the following connective tissues.

 Fibrous
 Cartilage
 Bone
 Blood vessel
 Skeletal muscle
 Smooth muscle
 Fat
 Astrocytes

Answer 18

 Fibous-Fibroma-Fibrosarcoma
 Cartilage-Chondroma-Chondrosarcoma
 Bone-Osteoma-Osteosarcoma
 Blood vessel-Angioma-Angiosarcoma
 Skeletal muscle-RhabdomyomaRhabdomyosarcoma
 Smoothmuscle -Leiomyoma-Leiomyosarcoma
 Fat-Lipoma-Liposarcoma
 Astrocytes-Astrocytoma-Malignant astrocytoma

Question 19

Describe the following 3 exceptions when naming tumors.

1. Fibroadenoma
   2.Lymphoma
2. Melanoma

Answer 19

Fibroadenoma: benign neoplasm of the breast

 Lymphoma: all lymphomas are malignant tumors
of lymphoid cells, although some are more malignant than others.

 Melanoma: this is a malignant tumor of
melanocytes and are actually epithelial in
nature.

 Sometimes called malignant melanoma (as
opposed to benign proliferations of melanocytes
termed naevi).

Question 20

What are benign proliferations of melanocytes called?

Answer 20

Naevi

Question 21

Describe the following exceptions when naming tumors.

Pleomorphic adenoma
Mesothelioma
Teratoma
Seminoma
Hydatidiform mole

Answer 21

Pleomorphic adenoma: Benign mixed tumor of salivary glands.

Mesothelioma: A tumor derived from mesothelial cells lining body cavities such as pleura. Can be benign or malignant.

Teratoma: Tumor composed of tissues derived from the three germ layers. It usually occurs in gonads.

Seminoma: Malignant tumor of seminiferous tubules.

Hydatidiform mole: Benign tumor of the placenta.

Question 22

Describe the following non-neoplastic growth disorders.

1. Hamartoma
2. Choriostoma
3. Polyp

Answer 22

Hamartoma: Disorganized benign tumor like tissue.

Choriostoma: Presence of normal tissue in an
abnormal location.

Polyp: Any growth or mass protruding from
mucus membrane

Question 23

Differentiate between dysplasia and anaplasia.

Answer 23

Dysplasia is the abnormal development or growth of cells within a tissue or an organ, which may be reversible or precancerous.

Anaplasia is the loss of differentiation or maturity in cells, which is seen as an irreversible condition and a sign of cancer.

Question 24

Outline the mechanism of Growth Disorders.

Answer 24

1.Polyclonal growth
2.Monoclonal growth

Question 25

Describe characteristics of Dysplasia.

Answer 25

 Dysplasia is a very important disorder of growth and differentiation.
 Since it is a pre-malignant condition.
 It has real clinical significance
 ‘halfway house’ between hyperplasia and neoplasia.
 increased cell number
 nuclear abnormalities
 hyperchromasia
 pleomorphism
 abnormalities of cellular differentiation
 Dysplasia may be reversible (at least in its early
stages)
 Dysplastic lesions are often pre-neoplastic.

For example:

 Dysplasia in the cervix associated with Human
papilloma virus (HPV) infection

 Dysplasia in the metaplastic squamous epithelium of the bronchus in smokers

Question 26

Define grading.

State the grading system for cancer.

Answer 26

Grade is the term used to denote the degree of differentiation of a tumor.

CANCER GRADING:
 Histological assessment of malignancy.
GRADE 1: Well differentiated
GRADE 2: Medium differentiation.
GRADE 3: Poorly differentiated.

Question 27

What is cancer staging?

Describe the staging system for cancer.

Answer 27

 CANCER STAGING: Clinical assessment of the spread of the tumor, based on TNM system.

1.(T) TUMOR SIZE
T0: No evidence of tumor is present.
T1-T4: Identify the size and extension of the tumor, with progressive enlargement and invasiveness.

2.(N) NODAL: Has it spread to any lymph nodes?

*N0: It has not spread to lymph nodes.
*N1: 1-3 regional nodes.
*N2: 4-6 regional nodes
*N3: Most severe spread to lymph nodes. 7+ regional nodes involved.
*Nx: lymph nodes are unable to be assessed.

3.(M) METASTASIS
M0: No metastases are present.
M1: Metastases are present.

Question 28

What is metastasis?

Answer 28

Spread of the tumor to a noncontiguous site.

Metastasis means that cancer has spread to a different part of your body part than where it started.

Question 29

Describe route of metastasis of cancer.

Answer 29

1. Trans coelomic (spread by seeding) - Spread by cavities such as the pleural, pericardial, and peritoneal cavities. It results in an effusion of fluid (exudate) into the cavity.

2.Lymphagenous (lymphatic) spread- This is spreading by lymph nodes and lymphatic vessels, and it is more typical of carcinomas.

The pattern of lymph node involvement depends on the site of primary neoplasm and natural pathways of lymphatic drainage at the site.

It is important to note the sentinel lymph node, which is the first lymph node in a regional lymphatic basin that receives lymph flow from a primary tumor.

3. Hematogenous spread-
   This is spreading via blood vessels, and it is mostly favored by sarcomas. Arteries are penetrated less readily than are veins because the increased velocity and pressure of blood flow would just “wash away” the tumor.

In veins and capillaries, flow is slower, allowing chances to invade.

*Since all portal area drainage goes to the liver and all caval blood goes to the lungs, the liver and the lungs are the most frequently involved secondary sites in hematogenous spread.

4. Implantation- e.g., by accidental spillage of tumor cells during surgery.

Question 30

Describe the process of metastasis.

Answer 30

1. Start with a primary tumor.
2. Enters into the basement membrane.
3. Enters into the Extracellular matrix.
4. Invades into vessel (Intravasation).
5. Forms a tumor embolus.
6. Extravasation
7. Develop blood vessels and forms a colony.

Question 31

Ultimately the importance of neoplasms lies in
their effects on patients.

Although malignant tumors are more
threatening than benign tumors. Any tumor, even a benign one, may cause morbidity and mortality depending on where it is.

Indeed, both malignant and benign tumors may
cause problems because of their anatomic or
physiologic effects

OUTLINE some of the clinical aspects of neoplasia.

Answer 31

(1) location and impingement on adjacent structures

(2) functional activity such as hormone synthesis or
the development of paraneoplastic syndromes

(3) bleeding and infections when the tumor ulcerates through adjacent surfaces

(4) symptoms that result from rupture or infarction,
and

(5) cachexia or wasting

Question 32

Outline some of local mass effects

Answer 32

 A small (1-cm) pituitary adenoma, though benign
and possibly non-functional, can compress and
destroy the surrounding normal gland and thus
lead to serious hypopituitarism.

 Cancers arising within or metastatic to an
endocrine gland may cause an endocrine
insufficiency by destroying the gland.

 Small benign intracranial neoplasm may cause
serious disorder by increasing the intracranial
pressure.

 Neoplasms in the gut, both benign and malignant, may cause obstruction as they enlarge.

 Infrequently, peristaltic movement telescopes the
neoplasm and its affected segment into the
downstream segment, producing an obstructing
intussusception.

 The erosive and destructive growth of cancers or the expansile pressure of a benign tumor on any natural surface, such as the skin or mucosa of the gut, may cause ulcerations, secondary infections, and bleeding.

Question 33

Define a paraneoplastic syndrome.

Answer 33

A set of signs and symptoms that is the
consequence of cancer in the body.

Signs and symptoms caused indirectly by substances produced by a tumor or as part of an immune response to it.

This causes night sweats, fever, and loss of appetite.

Question 34

How is a paraneoplastic syndrome different from a mass effect?

Answer 34

Is the consequence of cancer in the body but that,
unlike mass effect, is not due to the local
presence of cancer cells.

Question 35

What are the 2 main mediators of paraneoplastic syndrome?

Answer 35

1. Humoral factors (such as hormones or cytokines) excreted by tumor cells.
2. An immune response against the tumor.

Question 36

Name the disorder associated with lung carcinoma.

Answer 36

Example
Lung carcinoma associated with Cushing syndrome.