pathology lecture

2.  Cancer is one of the leading causes of death
worldwide.
 Emotional and physical suffering by the
patient.
 Different mortality rate …..
 Some are curable
 Others are fatal

3.  Neoplasia = latin word (new growth)
 Neoplasm = tumor
 Tumor = swelling
 Neoplasia means new growth and is
characterized by unceasing abnormal and
excessive proliferation of cells.

4.  Definition:
 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
 With the loss of responsiveness to normal growth
controls
Rupert Willis

5.  The study of tumors = Oncology
 Oncos = tumor + ology = study of
 "Oncology" is the study of tumors.
 ONCOLOGISTS
 DIFFERENTIATION: Extent to which
neoplastic parenchymal cell resemble their
normal parent cells, both morphologically
and functionally.
 Anaplasia: Irreversible loss of differentiation

6.  Classification
 Benign
 Malignant

7.  Benign tumors :It is tumor with relatively
innocent characteristics as :
 Will remain localized
 Cannot spread to distant sites
 Generally can be locally excised
 Patient generally survives

8. Characteristics Benign Malignant
1.Differentiation Well differentiated Ranges from well differentiated to
undifferentiated
2.Anaplasia No anaplasia Certainly present
3. Spread/Infiltration Remains localized Invades and penetrates the surrounding
tissue
4. Metastasis No metastasis Metastasize to regional lymph nodes and
distant organs
5. Rate of growth Usually slow except leiomyoma Usually rapid except cancer of cervix
grows slowly
6. Encapsulation Enclosed within capsule which separates
it from host tissues, except leiomyoma
Capsule never present
7.Gross appearance Degeneration, necrosis ulceration,
hemorrhage less frequent
Degeneration, necrosis ulceration,
hemorrhage more frequent
8. Clinical Effects Do not endanger life until vital organs
involved
Act as parasite and tends to kill the
patient whenever it grows
9.Recurrence Easily local removal-no recurrence Recurrence common

9.  Components of neoplasms:
1. Parenchyma: made up of proliferating parts of neoplastic
cells
 Determines biological behavior of tumor from which the
tumor derives its name
2.The stroma:
 made up of non-neoplastic, host-derived connective tissue
and blood vessels
 Provides support for the growth of the parenchyma
3. Desmoplasia- the excess of stromal component in tumor
is called desmoplasia and a such tumor is called scirrhous
tumor.

10.  Tumor is named on the basis of
 Based on the biological behavior :
 Benign and malignant
 Based on the cell or tissue of origin :
 One neoplastic cell type : lipoma,adenocarcinoma
 More than one neoplastic cell type : MIXED like
fibroadenoma
 More than one neoplastic cell type derived from
more than one germ-cell layer: teratoma

11.  Nomenclature
 Benign tumors:
▪ prefix + suffix
▪ Type of cell + (-oma)
 Examples:
 Benign tumor arising in fibrous tissue:
Fibro + oma = Fibroma
Benign tumor arising in fatty tissue:
Lipo + oma = lipoma

12.  Benign tumor arising in cartilage
chondro + oma = chondroma
 Benign tumor arising in smooth muscle
fibrous + oma = fibroma
 Benign tumor arising in skeletal muscle
Rhabdomyo + oma = rhabdomyoma

13.  Epithelial benign tumors are classified on the
basis of :
 The cell of origin
 Microscopic pattern
 Macroscopic pattern

14.  Adenoma : benign epithelial neoplasms
producing gland pattern….OR … derived from
glands but not necessarily exhibiting gland
pattern
 Papilloma : benign epithelial neoplasms growing
on any surface that produce microscopic or
macroscopic finger-like pattern

15.  Malignant tumors:
 Malignant tumor arising in mesenchymal tissue :
SARCOMA
▪ From fibrous tissue: Fibrosarcoma
▪ From bone : Osteosarcoma
▪ From cartilage : chondrosarcoma
 Malignant tumors arising from epithelial origin :
CARCINOMA
 Squamous cell carcinoma
 Renal cell adenocarcinoma

18.  Neoplasms composed of more than one
neoplastic cell type are called mixed tumors.
 two epithelial components, as in
adenosquamous carcinoma;
 two mesenchymal components, as in
malignant fibrous histiocytoma; or
 an epithelial and a mesenchymal component,
as in carcinosarcoma of the lung and
malignant mixed müllerian tumor (MMMT) of
the uterus.

19.  Teratoma:
 Teratoma contains recognizable mature or
immature cells or tissues representative of more
than one germ-cell layer and some times all three.
 Teratomas originate from totipotential cells such
as those normally present in the ovary and testis.

20.  MIXEDTUMORS: More than one type of
cells derived from same germ layer
 TERATOMAS
 HAMARTOMAS: Disorganized
overgrowth of mature cells indigenous to
that part
 CHORISTOMA: Presence of well
developed & normally organized tissue of
one organ in another

21.  Melanoma ( skin )
 Mesothelioma (mesothelium )
 Seminoma ( testis )
 Hepatoma (HCC also called)
 Invasive meningioma
 Leukemia (always malignant)
 Lymphoma ( lymphoid tissue )

23. 1. Gross/Clinical Features
2. Microscopic Features
3. Growth Rate
4. Local Invasion
5. Metastasis
6. Prognosis

24.  Dysplasia :
 Definiton: a loss in the uniformity of the individual
cells and a loss in their architectural orientation.
 Non-neoplastic and does not necessarily cause
cancer
 Or doesn’t mean cancer and is REVERSIBLE
 Occurs mainly in the epithelia
 Dysplastic cells shows a degree of :
pleomorphism, hyperchromasia,increased mitosis
and loss of polarity.

25.  Metastasis :
 Definition : the development of secondary implants
discontinuous with the primary tumor, possibly in remote
tissues.
 Cancers have different ability to metastasize
 Approximately 30% patients present with clinically evident
metastases.
 Generally, the more anaplastic and the larger the primary
tumor, the more likely is metastasis

26.  Metastasis : three pathways
 Lymphatic spread :
 Hematogenous spread :
 Seeding of the body cavities: pleural, peritoneal
cavities and cerebral ventricles

27. Lymphatic spread :
 favored by carcinomas
 Breast carcinoma  axillary lymph nodes
 Lung carcinomas  bronchial lymph nodes
Hematogenous spread :
 favored by sarcomas
 Also used by carcinomas
 Veins are more commonly invaded
The liver and lungs are the most frequently involved secondary sites
Seeding Body Cavities:
 Malignant neoplasm penetrate into natural cavity (pleural, pericardial,
peritoneal, subarachnoid and joint space)
 This mode of transmission is characteristic of cancers of ovary