Pathology Week 3 Flashcards
Characteristics of benign tumors
slow/limited growth, well circumscribed, lobulated, encapsulated, discrete, mobile, easily removed, localized to original tissue. Can be lethal.
Characteristics of malignant tumors
limitless growth, invasion or destruction of adjacent tissues including basement membrane, poorly demarcated margins
What is a hamartoma?
Disorganized growth/mass of indigenous tissue. Cells in right place but growth disorganized. Not a neoplasm
What is a Choristoma?
normal architecture in wrong location, congenital anomaly. Not a neoplasm.
What is the parenchyma?
functional part of tissue of an organ as distinguished from the connective and supporting tissue. In tumor, transformed neoplastic cells
What is the stroma?
Host: surrounding supportive (connective) tissue
What is dysplasia?
Loss of cell uniformity/orientation (epithelial)
What is desmoplasia?
Stromal reaction (fibrosis-collagen) to invasion
What is anaplasia?
Complete lack of differentiation (malignancy)
Epithelial neoplasms?
carcinomas
mesenchymal neoplasms?
sarcomas
Characteristics of differentiation?
size/shape, nuclear morphology, proliferative activity, glandular architecture
What are some characteristics of poor differentiation?
- Cells and nuclei become less uniform, acquire variation in size and shape
- Nuclei become large, irregular, hyperchromatic; ↑ nucleus/cytoplasm ratio
- Mitoses increase in number, become easy to find, with atypical shapes
- Glands become irregular with loss of polarity/orientation, haphazard growth
What does pleomorphic mean?
having more than one shape or form.
How does grading of tumors work?
Based on level of differentiation, from well differentiation (grade 1) to undifferentiated/anaplastic (grade 4)
What is a carcinoma in situ?
Shows marked dysplastic changes, involves full thickness of the epithelium, but is pre-invasive in that it has not invaded the basement membrane yet.
What are the 3 kinds of metastasis?
- lymphatic spread to regional lymph nodes (carcinomas)
- hematogenous spread to liver and lungs (carcinomas and sarcomas)
- Seeding of adjacent cavities (peritoneum, pleura) (carcinomas, typical of ovary)
What is E-cadherin?
It’s inactivation is believed to facilitate tumor invasion and metastasis because it helps mediate cell-cell interactions, which must be loosened to allow movement of malignant cells
What do metalloproteinases do?
Metalloproteinase degrades the extracellular matrix, facilitating cellular movement
How do chemokine receptors affect metastasis?
Chemokine receptors stimulate the movement of tumor cells through the extracellular matrix and help determine the target tissues for metastases.
How does VEGF affect metastasis?
Vascular endothelial growth factor stimulates the growth of new blood vessels to support metastatic foci.
How is tumor staging done?
TNM: T (primary tumor’s size), N (regional nodes, number, location), M (metastases, number, sites). Mainly used for carcinomas. Staging more important than grading.
What is a paraneoplastic syndrome?
is a disease or symptom that is the consequence of cancer in the body but, unlike mass effect, is not due to the local presence of cancer cells
What is an example of a paraneoplastic syndrome?
Venous thrombosis (trousseau sign) as a result of a hypercoagulable state from pancreatic cancer and others
How do tumors evade death/apoptosis?
p53, BCL2, BAX mutations
What do metastases look like?
Metastatic cancer commonly looks histologically like its primary. This principle is important for patient management, when biopsies may be helpful in identifying a source of a metastatic lesion of unknown primary.
