Integumentary System Pathology 1 - Basic Pathology, General Carcinogenesis Flashcards
What is a papilloma?
Benign tumor of epithelial cells projecting outward either micro- or macroscopically
What is a polyp?
Benign tumor projecting macroscopically into a lumen
What premalignant situation exists if dysplastic or neoplastic cells have not breached the basement membrane?
Carcinoma in situ
What are the four most common types of malignant tumors?
(1) Sarcoma: malignant tumor of mesenchymal tissue
(2) Carcinoma: malignant tumor of epithelial tissue
(3) Adenocarcinoma: carcinoma with a glandular pattern
(4) Squamous cell carcinoma: carcinoma arising from stratified squamous epithelium
Which cells are most susceptible to becoming neoplastic?
Epithelial cells (because they regenerate often).
What is the “two-hit hypothesis” of cancer development?
It takes more than one genetic mutation for a cell to become cancerous
What are some of the major sources of mutagenic and carcinogenic compounds?
(1) Tobacco products
(2) Food
(3) Water
(4) Chemical exposures
(5) Radiation exposures
(6) Drugs
What must occur for a cell to go through full neoplastic transformation and become a malignant tumor?
Multiple genetic abnormalities
What two types of genes are involved in carcinogenesis?
(1) Oncogenes
(2) Tumor suppressor genes
What is a proto-oncogene called after it mutates?
Oncogene. “Pro” suffix usually refers to precursors.
When tumor suppressor genes mutate, what may potentially occur in the cell?
The cell may potentially divide forever
As tumors enlarge, what do they promote around them?
(1) Neo-angiogenesis
(2) Lymphangiogenesis
How do cancer cells evade detection by the immune system?
They develop mutations altering cell surface markers and secrete immunosuppressive compounds
How do neoplastic cells facilitate local invasion into adjacent tissues?
(1) Loss of contact inhibition
(2) Secretion of enzymes, such as matrix metalloproteases, that dissolve connective tissue
What are two cancers that tend to metastasize by venous drainage and settle in specific sites in th ebody?
(1) Prostate cancer: pelvis and lumbar spine
(2) Lung cancer: brain