3: Neoplasia Flashcards
Neoplasia
New growth; a clonal process initiated by a genetic mutation conferring growth advantage on the cells involved
Are neoplasias benign or malignant?
Neoplasia encompasses both
Benign vs malignant
Benign: localized
Malignant: invades and metastasizes -> cancer
Ways benign tumors can cause great harm
Spinal cord compression, airway compression, hemorrhage, hormone secretion
Four types of cancer that are always malignant
- Melanoma
- Lymphoma
- Seminoma
- Leukemia
Why cant hematopoietic malignancies be benign?
Its impossible for them to stay localized - theyre in the blood!
Acute vs chronic leukemia
Acute: cancerous cells have halted maturation at the blast stage
Chronic: cancer cells consist of mature cells
What is unique about metastasis of GI cancers?
Can spread via all three routes
Sentinel LN biopsy
Tracer dye injected into a tumor -> first LNs to take up the dye are the sentinel nodes - these are removed and isolates the most likely site of metastasis for evaluation
Virchow node
Supraclavicular LN often associated with carcinoma in the thorax or abdomen
Why is Virchow’s node common in any CA of thorax or abdomen?
CA can metastasize into the thoracic duct -> L subclavian V -> Virchow’s node is along this
TNM Staging
T: tumor size
N: degree and manner of nodal Mets
M: presence/absence of distant mets
Most common three cancers in males vs females
Males: prostate, lung, colon/rectum
Female: breast, lung, colon/rectum
Cancer that causes the most death in males and females
Lung cancer
What sets many childhood cancers apart from adult cancers?
Germline mutations
Two reasons screening for CA works?
- ID cancers in early stages
2. ID cancers before they are cancers
P450 haplotypes
Can make people more protected from cancer or more susceptible
How does acute promyelocytic leukemia cause DIC?
Leukemic cells express tissue factor -> activates factor X -> endothelial injury and anticoagulant dysfunction -> thrombin release -> ischemic damage
What does DIC stand for?
Disseminated intravascular coagulation
Direct vs indirect carcinogen
Direct: carcinogenic immediately
Indirect: a metabolic process must take place for substance to become an active carcinogen
Cytochrome p450 function in carcinogenesis
Converts most indirect carcinogens into their active form
Pyrimidine dimers and what fixes them
Dimers that distort DNA due to UV rays; fixed by NER (nt excision repair)
What happens if you lack NER?
Xeroderma pigmentosum - sporadic melanomas
Pseudomyxoma peritonei
A distinct subtype of seeding body cavities, most commonly due to a primary carcinoma of the appendix
