superficial introduction to the topic for bachelor level

1. Neoplasia
Dr. Saugat Chapagain

2. Introduction
Neoplasia- new growth of neoplasm or tumor
- Mass of tissue formed as a result of abnormal, excessive,
uncoordinated, autonomous and purposeless proliferation of
cells even after cessation of stimulus for growth which caused
it.
Oncology – study of tumors
Components:
1. Parenchyma - comprised by proliferating tumor cells and
determines the nature and evolution of tumor.
2. Supportive stroma- composed of fibrous tissue and blood
vessels and provides framework for parencchymal cells to
grow on.

3. Special categories
1. Mixed tumors –
• When 2 types of tumors are combined to form one tumor.
• Adenosquamous ca. (endometrium), carcinosarcoma (thyroid), collison tumor
(2 diffferent cancer in same organ that do not mix together), pleomorphic
adenoma (epith. + mesenchymal)
2. Teratoma
• Tissue types arising from totipotent cells from the germ cell layers.
• Most common (gonadal teratoma)
3. Blastomas (embryomas)
• Arise from embryonal/ partially differentiated cells.
• Frequent <5 yrs of age.
• Neuroblastoma, nephroblastoma, retinoblastoma, etc.
4. Hamartoma
• Malignant disorganized cells of tissues indigenous to the particular organ
• E.g. hamartoma of lungs
5. Choristoma
• Ectopic islands of normal tissue.
• a/k/a heteropia (not a true tumor)

4. Classification
On basis of behaviour
• Benign (-oma)
• Malignant (-carcinoma/ - sarcoma)
On basis of tissue of origin
• Epithelial
• Mesenchymal
• Mixed
• Teratomas

9. Characters of benign tumor
• Differentiation – well differentiated
• Rate of growth – slow, small size, stroma is formed
• Capsule formation – composed of surrounding connective
tissues (localized concealment)
• No metastasis
• Mostly asymptomatic
• Minimal recurrence.

10. Clinical effects
• Depends on size, position, mechanical pressure, obstruction
and production of hormones.
• Local effect
• Discomfort and mechanical difficulty
• Obstruction (obstructive jaundice by GB papilloma)
• Ulceration, secondary bacterial infection and hemorrhage
• Torsion
• Pressure effect on adjacent tissues
• Hormonal effect:
• E.g. adenoma, thyrotoxicosis.
• Malignant transformation:
• E.g. adenoma of colon

11. Characteristics of malignant
tumor
• Differentiation and anaplasia – cytological abnormalities
• Well differentiated  poorly differentiated  anaplastic
• Pleomorphism – variation of size and shape
• Architecture is disturbed
• N:C ratio is increased
• Nuclear pleomorphism
• Rate of growth – rapid
• Local invasion (+)
• Non capsulated
• Metastasis (+)
• Recurrence (+) after surgical removal

12. Clinical effects of malignant
tumors
• Almost always fatal if untreated
• S/S due to size, postion, mechanical pressure, invasion, obstruction,
metastasis and systemic effects.
• Local effects:
• Obstruction (intestinal)
• Invasion and destruction of surrounding tissue (ca. cervix invades the ureter)
• Ulceration, secondary infection and hemorrhage.
• Pain
• Hematological changes:
• Anaemia, neutrophilic leucocytosis and occasionally eosinophillia.
• Starvation/ dysphagia – in ca. of mouth, oesophagus and stomach
• Cancer cachexia – wasting with loss of body fat d/t fat metabolism
• Effect of metastasis – depends on site of metastasis.
• Impairment of immune response.

13. Routes of metastasis
• local spread
• Lymphatic
• Usu. carcinomas
• Hematogenous
• Usu. Sarcomas
• Along body cavities and natural passages
• Transcoelomic – Krukenberg tumor (of stomach in ovaries)
• Spread along epithelial lined surfaces - ovaries to fallopian tubes
• Spread via CSF – meningeal carcinoma
• Implantation – iatrogenic, via. injury sites.

14. Staging
• TNM staging:
• T0 to T4 – in situ lesion to largest and most extensive primary tumor
• N0 to N3 – no nodal involvement to widespread LN involvement
• M0 to M2 – no metastasis to disseminated hematogenous metastasis
• AJC (american joint committee)
• Stage 0 – 4
• Primary tumor, nodal involvement, distant metastasis

15. Laboratory diagnosis
• Cytology
• Histology
• Tumor markers
• Frozen sectioning
• Immunocytochemistry
• Immunofluroscent microscopy
• Molecular diagnosis
• Flow cytometry
• Electron microscopy

16. Thank you