– Neoplasm: mass of tissue that grows excessively & keeps growing even if you remove the stimulate that started it off.
– Benign tumor= innocent – acting tumor
– Malignant tumor= evil – acting tumor
General characteristics of Neoplasia
– slow growing
– Non invasive
– well differentiated
– stay localized
– fast growing
– poorly differentiated
– The only indisputable equality of malignancy is metastasis
– Benign tumor can’t metastasize , Malignant tumors can.
– If it is metastatic , it must be Malignant .
– if lung cancer spreads to liver , the cancer cells in the liver are lung cancer cells . The disease called metastatic lung cancer “it is not liver cancer’’
– primary site = Lung
– Secondary site = Liver
– 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 .
– papilloma-has finger like projections .
– polyp- projects upward , forming a lump
– cystadenoma-has hollow spaces ‘’cysts’’ inside.
– carcinomas – arise in epithelial tissue.
– adenocarcinoma- Malignant tumors of glandular cells
– squamous cell carcinoma- Malignant tumor of squamous cells.
– Sarcomas – arise in mesenchymal tissue .
– chondrosarcoma- Malignant tumor of chondrocytes.
– angiosarcoma- Malignant tumor of blood vessels.
– rhabdomyosarcoma- Malignant tumor of skeletal muscle cells .
Mixed Tumor show divergent differentiation.
e.g. -pleomorphic adenoma-glands+fibromyxoid stroma
– fibroadenoma- glands + fibrous tissue .
– Not to be confused with teratomas.
– Malignant tumor that sound benign .
– lymphoma. -mesothelioma.
– melanoma. -seminoma.
– Non-tumors that sound like tumors:
– hamartoma-mass of disorganized indigenous tissue.
– choristoma-hetero topic rest of cells.
– Names that seem to come out of now here:
– Nevus -leukemia
– hydatidiform mole
• Differentiation and anaplasia
– Differentiation= how much the tumor cells resemble their cells of origin
– weel differentiated – closely resemble normal countepart
– moderately differentiated – sort of resemble normal countepart
– poorly differentiated – doesn’t resemble normal countepart
• Benign Tumors are usually well differentiated
• malignant Tumors can show any level of differentiated
– Anaplasia = a state of complete un –Differentiaion
– literally “ to form ( – plasia ) backword ( ana – )
• Misnomer cells don’t differentiate
• just mean cells are very poorly differentiated
• Almost always indicates malignancy
Anaplastic cells show:
• hyperchromatic , large nuclei
• bizarre nuclear shapes , distinct nucleoli
• losts of mitosis , and atypical mitosis
• architectural anarchy
– Dysplasia = disorderly ( dys – ) growth ( – plasia )
– Dysplasia is used to describe disorderly change in non- neoplastic epithelial cells
• Graded as mild , moderate , or sever
– mild – moderate : usually reversible
– sever : usually progresses to carcinoma in situ ( CIS)
– Next step after CIS : invasive carcinoma
Dysplastic cells show:
• hyper chromatic , large nuclei
• losts of mitosis
• architectural anarchy
Rate of growth
• Malignant tumors grow faster than benign ones
• poorly differentiated tumors grow faster than Well differentiated one
• Growth is dependent on :-
– blood supply
– hormonal factor
– emergence of aggressive sub – clones
• Metastasis = development of secondary tumor implants in distant tissues.
• Half of all patients with a malignancies have metastasize at the time of diagnosis.
• Metastasis depends on:
– Type of tumor.
– Size of tumor.
– Degree of differentiation of tumor.
• Three ways tumor metastasize:
– Lymphatic spread.
– Hematogenous spread.
• Lymphatic spread:
– Tumor spreads to local lymph nodes
– Sentinel lymph node first.
– Moves through thoracic duct.
– Empties into subclavian vein.
– Carcinomas like to spread this way.
• Hematogenous spread:
– Veins are easier to invade than arteries.
– Liver and lungs are most common metastatic destinations.
– Some tumor like other sites better:
- Prostate à Bone
- Most lung cancer à adrenals, brain
– Sarcomas like to spread this way [but so do carcinomas].
Epidemiology on Neoplasms
• Cancer incidence.
• Environmental variables.
• Acquired preneoplastic syndromes.
• 1.4 million new cases of cancer 2006 usa.
• 565.000 death from cancer 2006 usa.
• Cancer is 2nd leading cause of death after heart.
• Most common cancers:
* men: prostate
* women: breast
• Deadliest cancers:
* men and women: Lung
• Death rate have changed over past 4 years.
• Decrease in death rate:
– Cervical cancer ( pap smear).
– Colon cancer ( earlier detection).
– Breast cancer (earlier detection).
– Lung cancer in men (less smoking).
– Some type of leukemia ( new treatment).
• Increase in death rate:
– Lung cancer in women ( more smoking)
• Breast cancer death rate in US is 5x than japan.
• Stomch cancer death rate in japan is 7x than US.
• Liver cancer infrquent in US, common in africa.
• Probably due to environmental factor(not hereditary )factor .
• Most sporadic cancer are caused by environmental factor.
• Sun light : skin cancer.
• Smoking: lung cancer.
• Alcohol: liver& breast cancer.
• HPV: cervical carcinoma.
• Cancer is most frequent at two extremes of age
* frequency of cancer increase with age
* most cancer deaths occur between 55-75 .
* 10% of all childhood deaths.
* leukemia/lymphoma, CNS tumors, sarcoma.
• Three categories of heredity cancer:
1. Inherited cancer syndrome.
2. Familial cancer.
3. Syndrome of defective DNA repair.
Inherited cancer syndrome
• Dominantly inherited.
• Familial polyposis coli
• Most common sporadic cancers have familial formation.
• Breast, colon, brain, ovary.
• Occur earlier are often deadlier.
Syndrome of defective DNA repair
• Recessively inherited.
• Xeroderma pigmantosum.
Acquired preneoplastic syndromes
• Persistent regeneration cell replication
* chronic skin fistula – squamus cell carcinoma
* cirrhosis – liver cancer
• Hyperplastic and dysplastic proliferation
* Atypical endometerial hyperplasia àendometrial cancer
* Dysplastic bronchial mucosa à lung cancer.
• Chronic atrophic gastritis à stomach cancer.
• Chronic ulcerative colitis à colon cancer.
• Leukoplakia à squamous cell