1. TUMORS and NEOPLASM

2. Neoplasia and Neoplasm
Neoplasm is an abnormal mass of tissue as a result of neoplasia
Neoplasia (new growth in Greek) is the abnormal proliferation of cells.

3. Definitions
Neoplasm is mass of tissue that grows excessively, and keeps growing even if you remove the stimulus that started it off
Types: Benign tumor and Malignant tumor

4. Benign Tumors Malignant Tumors Definitions Large Small Fast-growing
Invasive
Poorly-differentiated
Metastasize
Infiltrate, invade, destroy surrounding tissue.
Then metastasize to other parts of body.
Small
Slow-growing
Non-invasive
Well-differentiated
Stay localized
Stay where they are.
Can’t invade or metastasize.

5. Benign versus Malignant

6. 1- Benign Tumors
Usually designated by adding “-oma” to cell type
Adenoma – benign tumor arising from glandular cells
Leiomyoma – benign tumor arising from smooth muscle cells
Chondroma – benign tumor arising from chondrocytes
Other benign tumor names
Papilloma – has finger-like projections
Cystadenoma – has hollow spaces (cysts) inside

7. A- Carcinomas – arise in epithelial tissue
2- Malignant Tumors
A- Carcinomas – arise in epithelial tissue
Adenocarcinoma – malignant tumor of glandular cells
Squamous cell carcinoma – malignant tumor of squamous cells
B- Sarcomas – arise in mesenchymal tissue
Chondrosarcoma – malignant tumor of chondrocytes
Angiosarcoma – malignant tumor of blood vessels
Rhabdomyosarcoma – malignant tumor of skeletal muscle cells
Mesenchymal tissue are capable of developing into connective tissue, bone, cartilage, the lymphatic system, and the circulatory system

8. Tumor Characteristics Differentiation and Anaplasia
Differentiation is how much the tumor cells resemble their cells of origin.
well-differentiated – closely resembles
moderately-differentiated – sort of resembles
poorly-differentiated – doesn’t resemble
Benign tumors are usually well-differentiated
Malignant tumors can’t show any level of differentiation.

9. Rate of Growth Generalizations
Malignant tumors grow faster than benign ones.
Poorly-differentiated tumors grow faster than well-differentiated ones.
Growth is dependent on:
Blood supply
Hormonal factors
Emergence of aggressive sub-clones

10. Metastasizing carcinoma
Carcinoma in situ
Invasive carcinoma
Metastasizing carcinoma
Invasive carcinoma

11. Metastasis
Metastasis is development of secondary tumor in distant tissues
Half of all patients with malignancies have meets at the time of diagnosis!!
Metastasis depends on:
Type of tumor
Size of tumor
Degree of differentiation of tumor

12. Three ways tumors metastasize
Metastasis
Three ways tumors metastasize
Seeding
Lymphatic spread
Hematogenous spread

13. Three ways tumors metastasize
Metastasis
Three ways tumors metastasize
1. Seeding
Tumor invades body cavity
Bits break off and implant on peritoneal surfaces
Ovarian cancer
2. Lymphatic spread
Tumor spreads to local lymph nodes
Sentinel lymph node first
Moves through thoracic duct
Empties into subclavian vein
Carcinomas of the breast

14. Metastasis 3. Hematogenous spread
Veins are easier to invade than arteries
Liver and lungs are most common metastatic destinations
eg. Sarcomas

15. Cancer Incidence Decrease in death rates for
Most common cancers
Men: Prostate
Women: Breast
Deadliest cancers
Men: Lung
Women: Lung
Decrease in death rates for
Colon cancer (earlier detection)
Breast cancer (earlier detection)
Lung cancer in men (less smokers)
Some types of leukemia (new treatment)
Increase in death rates for:
Lung cancer in women (more smokers)

16. Carcinogenic Agents
Chemicals
Radiation
Bugs/viruses

17. 1- Chemicals Carcinogenic Agents Direct-acting agents
Indirect-acting agents
Require conversion to become carcinogenic
Examples:
hydrocarbons (in tobacco, charred meats)
aflatoxin B (from Aspergillus-infected grains, nuts)
nitrites (food preservative)

18. Causes chromosome breakage, translocations
Carcinogenic Agents
2- Radiation
Ionizing radiation
Causes chromosome breakage, translocations
Examples:
Unprotected miners: lung cancer
Atomic bomb survivors: leukemia, other cancers
Therapeutic head/neck radiation: thyroid cancer

19. Carcinogenic Agents 3- Bugs HTLV-1: T-cell lymphoma
Human papilloma virus: Cervical cancer
Epstein Bar virus: various lymphomas
Hepatitis B and C: hepatocellular carcinoma