2. INTRODUCTION:
Neoplasia: New growth.
Hence a new growth produced is called as neo plasam or tumour.
• In the body some cells have limited proliferation and some cells have continious proliferation
through out life.
• Neoplastic cells lose control and regulation of replication and form an abnormal mass of tissues.
3. Definition:
A mass of tissue formed as a result of abnormal, exessive
,uncoordinated,autonomous and purposless proliferation of cells even
after cesation of stimulus for grwouth which caused it.
Oncology:
Oncos- tumor ,logy- study
hence ,the branch of medical science which deals with the study of
tumors is called as oncology .
4. Nomenclature:
All the tumor hqve 2 types of cells namely
1. Paranchymal cells-
2. Supportive strauma-
Paranchymal determines the nature and evolutin of the tumor and supportive
straumaprovides the framework on which the paranchymal tumour grow.
Based on paranchymal component compromising the tumour the nomenclature
is made like
Melanoma- Carcinoma of melanocytes
Hepatoma- Carcinoma of hepatocytes
Lymphoma- Carcunoma of lympocytes
Seminoma- Carcinoma of testis
5. Leukamia – Cancer of blood forming cells
All the benign tumour’s are denoted by the suffix ‘oma’ but the malignant tumours
of the epithelial origin are also have the suffix ‘ oma’ hence calle Carcinoma and
the malignant tumours of the mesenchymal cells is called as Sarcomas ( Sarcos –
fleshy).
6. Classification:
I.Based on the nature of tumour- 2 types namely
1. Benign : Have slow growth,not spreads to the other organ and not gives much
difficulty to host.
2. Malignant : Have rapid growth ,spreads to the other systems of the body and
may cause the death of the host .
7. Cont....
II.Special catogoriese of tumours 5 types
1. Mixed tumour’s:When the 2 types of tumours combined in the same tumour it
iscalled ad mixed tumour.
Ex:Adenosquamous carcinoma is the combination of adenocarcinoma and the
squamous cell carcinoma in the endometrium.
2.Teratomous(gonadal teratomas) : These tumours are made up of a mixture of
various tissue types arising from the 3 layers like ectoderm ,endoderm and
mesoderm.Most common sites are ovariese and testis.
8. Cont....
3.Blastomas(Embryomas) : These are the group of malignant tumours which
arise from the embryonal cells.Hence most common in infants in children .
Ex: Hepatoblastoma
4.Hamartoma: These are benign tumour which is made up of mature but
disorganised cells of tissues indigenous to the piticular organ.
Ex: Hamartoma of the lung consists of mature cartilage,mature smooth muscles
and epithelium but they are jumbled up as a mass.
5.Choristoma: Its the name given to the ectopic islands of normal tissue.
9. Difference between benign and malignant tumours:
Feature Benign Malignant
I.Clinical and gross
features
1. Boundries
1. Sorrounding tissue
2. Size
3. Secondary changes
Encapsulated or well
circumscribed
Often compressed
Usually small
Occur less ften
Poorly circumscribed and
irregular
Usually invaded
Often larger
Occure more often
10. II.Microscopic features
1. Pattern
2.Basal polarity
Usually resembles the
tissue of origin closely
Retained
Often poor resembles to
tissue of origin
Often loss
3.Pleomorphism
4.Nucleo – cytoplasmic
ratio
5.Anisonucleosis
Usually not present
Normal
Absent
Often present
Increased
Generally present
11. 6.Hyperchromatism
7.Mitosis
Absent
May b present but are
always typical mitosis
Often present
Mitotic figures increesed
bt atypical n abnormal
8. Tumour gaint cells May b present bt without
nuclear atypia
Present with nucear atypia
9.Chromosomal
abnormalitiese
10.Function
Infrequent
Usually well mainained
Invariably present
May b retained,lost or
becime abnormal
12. III .Growth rate Usually slow Usually rapid
IV.Local invaion Often compresses the
sorrounding tissues
without invading or
infiltrating them
Usually infiltrates and
invades the adjescent
tissues
V.Metastasis
VI.Prognosis
Absent
Local cimplications
Frequently present
Death by local and
metastatic cimplications
