Exam #2: Neoplasia III Flashcards
(61 cards)
Generally, how does local invasion occur?
Invasion & penetration of basement membrane leading to:
- Invasion of adjacent organs
- Penetration of the body cavity
- Penetration of lymphatics
- Penetration of small venules or capillaries
What are the four steps to the invasion of the ECM?
1) Detachment of the tumor cells from each other
2) Attachment to the matrix component
3) Degradation of ECM
4) Migration of tumor cells
Describe the process of detachment. What molecules normally mediate attachment?
E-cadherins attach tumor cells to each other; in many malignancies, E-cadherin is NOT produced
How do invasive tumor cells attach to the matrix?
Laminin & laminin receptors present
What enzymes facilitate degradation of the ECM?
Tumor cells release or fibrobasts/ inflammatory cells release collagenases (MMP) to degrade type IV–basement membrane– collagen i.e. the type IV collagenases
What facilitates migration of tumor cells?
- Tumor binding to fibronectin
- Autocrine motility factors produced by tumor cells
What is the definition of metastasis?
Discontinuous tumor implantation to different sites, from the site of origin
Outline the four general steps of metastasis.
1) Invasion of basement membrane
2) Movement through ECM
3) Vascular dissemination
4) Homing
List the factors that facilitate vascular dissemination.
- CD44 expression on tumor cells seems to favor metastasis
- Platelets protect the tumor cells in the blood
Describe how metastasis by lymphatic vessels occurs.
1) Passage to regional lymph nodes
2) Slow growth and passage along the lymph node chain
3) Embolism and drainage to the thoracic duct
4) SVC–>Blood stream
5) Circulation of cancer cells in the blood
6) Logement in capillaries at distant sites
What are the three routes of metastasis?
1) Seeding of body cavities
2) Lymphatic spread
3) Hematogenous spread
What cancers seed to the peritoneal cavity?
Ovarian cancer
Colorectal cancer
Pancreatic carcinoma
What cancers seed to the pleural cavity?
Primary lung cancer
Metastatic lung cancer
What cancers seed to the sub-arachnodid space?
Glioma
Glioblastoma
What is the most common method of metastasis? What types of cancer is this method of metastasis most commonly seen in?
Lymphatic spread
*****Note that this is more common in carcinoma rather than sarcoma
Describe the clinical presentation of lymphadeopthy associated with cancer.
- Enlarged lymph nodes
- Hard
- NON-TENDER i.e. painless
**Tenderness is associated with inflammatory processes & is a good sign
How do carcinomas and sarcomas typically spread?
Carcinoma= lymphatic spread
Sarcoma= hematogenous
What are the exceptions to the lymphatic spread of carcinomas?
1) Folliclar carcinoma (local invasion)
2) Renal cell carcinoma (hematogenous)
3) Hepato-cellular carinoma (hematogenous)
What is the exception to the hematogenous spread of sarcomas?
Rhabdomyosarcoma
*****Note that this is malignant striated muscle neoplasm
What are the sites commonly involved in hematogeouns spread?
Tumor typically prefer to metastasize to low pressure areas in the veins, especially in the liver & lungs
What is the difference between an organ with a single mass vs. multiple gross masses?
Single= unlikely metastasis
Multiple= likely metastasis
What is central mass umbilication?
Central ischemic necrosis
What is the sentinel lymph node?
The first regional lymph node that receives flow from a primary tumor
How are sentinel lymph nodes detected?
Radio labeled tracers or blue dyes
