1. Neoplasia (1 of 6) Ali Al Khader, M.D. Faculty of Medicine
Al-Balqa’ Applied University

2. Introduction = new growth Oncology = study of neoplasia
Genetic/epigenetic basis
Neoplasms are clonal
Accumulation of mutations…more are accumulated in malignant ones
See next slide

3. With accumulation of mutations, features of malignancy are produced
More dysregulated autonomous growth (self-sufficiency in growth signals)
More lack of response to inhibitory signal
Evasion of apoptosis
Limitless replicative potential
More development of angiogenesis
Ability to invade surrounding tissues
Reprograming metabolic pathways
Evasion of the immune system
With more mutations more genomic instability vicious cycle

4. Nomenclature

5. Hamartomas and choristomas

6. Well-differentiated Anaplastic
-more N/C ratio
-more nuclear pleomorphism
-more hyperchromasia
-more mitoses
-more abnormal mitoses
-more large (giant) cells
-more bizarre cells
-less structures resembling original tissue
-more coarse clumped chromatin
What is dysplasia?

7. Benign Malignant Less mutations More mutations
Better differentiation (more resemblance to original tissue)
Worse differentiation (less resemblance to original tissue)…more to be anaplastic (anaplasia = total undifferentiation) than benign
Less mitoses
More mitoses
Mitoses are more likely to be abnormal than in benign
Stroma for supply is present
Stroma for supply is also present
*Note: some cancers have abundant fibrous stroma (= desmoplasia)
Slower growth…with some exception like?
Faster growth
No invasion
Invasion
Some with a capsule
Mostly no capsule
More circumscribed (well-defined)
Less circumscribed (ill-defined)…infiltrative
No metastasis
Metastasis

8. Metastasis and dissemination
Basal cell carcinomas…almost always non-metastatic
…also primary tumors of the central nervous system
Bone sarcomas…usually already spread to lungs at diagnosis
with differentiation and size…with exceptions
3 ways of dissemination

9. Metastasis and dissemination, cont’d
Medulloblastoma or ependymoma…through CSF in ventricles to meningeal surfaces of brain/spinal cord
Carcinoma…lymphatics, not only through lymphatics
Sarcoma…blood, not only through blood
Lung carcinomas regional bronchial lymph nodes tracheobronchial and hilar nodes

10. Metastasis and dissemination, cont’d
Breast:
…usually upper outer quadrant axillary lymph nodes
…medial breast lesions nodes along internal mammary artery
Sentinel lymph node???
Enlargement of nodes near cancer are not necessarily involved by the cancer
both may seed supraclavicular or infraclavicular nodes

11. Metastasis and dissemination, cont’d
Veins are penetrated easier than arteries
The liver and lungs are the most frequently involved secondary sites in hematogenous dissemination
Vertebral metastases of thyroid and prostate cancers…through the paravertebral plexus
Renal cell carcinoma…renal vein…may then spread through IVC
Prostatic carcinoma…bone
Lung…adrenals and brain
Neuroblastoma…liver and bones
Skeletal muscles are rare sites for metastasis

12. Epidemiology of cancer
Cervical cancer deaths markedly
Started to decline

13. Epidemiology of cancer, cont’d
Environmental more than genetic
Some geographic areas are with high incidence of smoking & alcoholism
Dietary fat and fibers colon cancer…differences between the West & Africa
Death rates from breast cancer are about four to five times higher in the United States and Europe than in Japan
The death rate for stomach carcinoma in men and women is about seven times higher in Japan than in the United States
Liver cell carcinoma is relatively infrequent in the United States but is the most lethal cancer among many African populations
Cervical cancer and its risk factors

14. Epidemiology of cancer, cont’d
Most cancer deaths occur between ages 55 and 75
The major lethal cancers in children are leukemias, tumors of the central nervous system, lymphomas, and soft tissue and bone sarcomas
…also retinoblastoma occurs mainly in pediatric age group

15. Epidemiology of cancer, cont’d
Occupational hazards

16. Epidemiology of cancer, cont’d
no more than 5% to 10% of all human cancers fall into one of these three categories
40% of retinoblastoma cases are hereditary
Inherited predisposition to cancer
-early age at onset
-tumors arising in two or more close relatives of the index case
-sometimes multiple or bilateral tumors
-not associated with specific marker phenotypes

17. Epidemiology of cancer, cont’d
Acquired preneoplastic lesions
…some are due to chronic tissue injury or inflammation
…their removal or reversal may prevent the development of a cancer
…examples: -Squamous metaplasia and dysplasia of the bronchial
mucosa…smokers
-Endometrial hyperplasia
-Leukoplakia of the oral cavity, vulva, or penis
-Adenomas of the colon

18. Thank You