Neoplasia i.e tumor has major two categories viz, benign and malignant. We will discuss about their difference and spread in normal human body.

1. Prepared by: Anish Dhakal (Aryan)
anishdhakal718@gmail.com
MBBS Student
Patan Academy of Health Sciences

2. Objective
• Definition of Neoplasia
• Nomenclature
• Characteristics of Benign and Malignant
Tumor
• Difference between Benign and
Malignant Tumor
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4. NEOPLASIA
“ Neoplasm is an abnormal mass of tissue,
the growth of which exceeds and is
uncoordinated with that of normal tissue
and persists in the same excessive manner
after the cessation of stimuli which evoked
the change” -Rupert Willis(1950)
Tumors have two basic components
1. Parenchyma
2. Stroma
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5. Nomenclature
Origin of tumor
Epithelial
Benign
Adenoma
Papiloma
Malignant
Adenocarcinoma
Papillocarcinoma
Mesenchymal
Benign
Fibroma
Lipoma
Malignant
Fibrosarcoma
Liposarcoma
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7. Benign Vs Malignant Tumor
• Differentiation and Anaplasia
• Rate of Growth
• Local Invasion
• Metastasis
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8. Differentiation and Anaplasia
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10. Differentiation
• Extent to which neoplastic parenchymal
cells resemble normal cells of origin
• Benign tumors are well differentiated
• Lack of differentiation = Anaplasia
(Hallmark of Malignancy)
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11. Anaplasia
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12. Anaplasia
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13. Hyperplasia, Dysplasia and
Neoplasia???
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14. Rate of Growth
• Malignant tumors grow faster than
benign ones.
• Poorly-differentiated tumors grow
faster than well-differentiated ones
• Growth depends on:
Blood supply
Hormonal factors
Emergence of aggressive sub-clones
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16. Local Invasion
• Benign tumors
•Stay where they are
•Can’t invade or metastasize
•Usually encapsulated
• Malignant tumors
•Infiltrate, invade, destroy
surrounding tissue
•Metastasize to other parts of body
•Not encapsulated 16

17. Local Invasion
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18. Metastasis
• Development of secondary implants on
distant tissues
• Metastasis depends on:
Type of tumor
Size of tumor
Degree of differentiation of tumor
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21. Metastasis
• Invasion of ECM
Loosening of tumor cells
Degradation of ECM
Attachment to ECM
Migration & invasion by
tumor cells
• Vascular dissemination
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22. Where to metastasize?
• Vascular and lymphatic drainage of the
primary tumor
• Expression of adhesion molecules on
target organs
• Chemokine expression by target tissues
• Receptive stroma
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