Lecture 8: Neoplasia Flashcards
What at the mechanisms of invasion
- Impairment of cell adhesion (ex: E-Cadherin inhibition)
- Basement membrane degradation via proteases
- Extension into permissive tissue- cleavage of basement membrane proteins generate sites that bind to receptors on tumor cells and stimulate migration
Describe the stages of invasion and metastasis
- Transformed cells must detract from main mass, adhere and penetrate basement membrane and enter ECM
- Intravasation: extension through endothelium- interacting with lymphoid cells and coating with platelets (form tumor emboli)
- Extravasation: extension back through endothelium, formation of metastatic deposits and angiogenesis
What is the preferred metastatic route for sarcomas
Hematogenous
What is the 1st capillary bed the vena cava hits and what tumors is that the most common route for
Vena cava—> 1st capillary bed=lung
Most common route for mammary, skin, soft tissue, bone and thyroid tumors
What is the 1st capillary bed for portal vein and what tumors is that the most common metastatic route for
Portal vein—> 1st capillary bed—> liver
Most common route for gastrointestinal and pancreatic tumors
What is the most preferred metastatic route for carcinomas
Lymphatics due to large gaps
What is the most common route of metastasis for mesotheliomas and reproductive tumors
Transcoelomic exfoliation and implantation
What type of tumor is this and what route did it likely use. What is the giant purple clump of cells representative of
Mammary gland Adenocarcinoma with metastasis to lymphatic vessels
Tumor emboli formed- giant clump of purple cells
What kind of tumor is this and what metastasis route did it use
Cholangiocellular carcinoma with transcoelomic exfoliation and implantation
Where do prostatic carcinomas like to metastasize to
Bone
Where do osteosarcomas like to metastasize to
Lung
What the primary effects of tumors
- Loss of function
- Pain and discomfort
What are paraneoplastic syndromes
Symptom complexes that can’t be directly attributed to local or distant tumors
What types of tumors is hypercalcemia commonly associated with
- Lymphoma in dogs (20-40%) and cats
- Apocrine Adenocarcinoma of anal sac in dogs
What are the sources of increased Ca2+
- Increased Ca2+ reabsorption, decreased phosphate reabsorption: promoted by parathyroid hormone related protein (PTHrP: Adenocarcinoma of anal sac)
- Release from bones- osteoclasts are stimulated by PTHrP
- Increased absoprtion in the intestines
What type of tumor is this and what is a paraneoplastic syndrome associated with it
Tumor: apocrine Adenocarcinoma of anal sac
Paraneoplastic syndrome: hypercalcemia- PTHrP
What is the clinical presentation of anorexia and cachexia as a paraneoplastic syndrome
Anemia, weakness, fatigue, weight loss, weak immune response
What are the common mechanisms of anorexia and cachexia as a paraneoplastic syndrome
- Decreased caloric intake
- Metabolic alterations: altered sensitivity to insulin, amino acids get directed from protein synthesis or gluconeogensis
- Increased catabolism: exceeds synthesis of proteins- reduced muscle mass, poor wound healing, low albumin
- Cytokine release: TNF-alpha encourages lipid breakdown
What type of tumor is this and what secondary/ paraneoplastic syndrome can it cause
pituitary adenoma—> increase ACTH—> results in Cushing disease
What tissue is this? Describe the appearance and what could have caused this
adrenal gland: cortical hyperplasia
Can be a result of hyperadrenocorticism due to excessive glucocorticoids
What is wrong here? What could cause this? What disease is associated with this
skin showing calcinosis cutis (dystrophic calcification). Likely Cushings disease
What paraneoplastic syndrome can a pancreatic islet cell tumor cause
Increased insulin production—> leading to hypoglycemia
What is the size of a tumor where you can have favorable size, discrete margins
3.0cm or less
What is the size if tumor where you have an unfavorable site or infiltrative margins
3 cm or more
What surgical margin technique is used here and what kind of tumor
Inking- mast cell tumor
What kind of tumor? Monomorphic or pleomorphic? What kind of growth pattern?
Growth pattern: sheets
Monomorphic
Tumor: MCT
