Neoplasia Flashcards
Neoplasm
An abnormal mass of tissue, whose uncoordinated and excessive growth exceeds that of normal tissues and persists after the cessation of the initial stimulus.
Are tumors autonomous?
Yes, but they depend on the host for nutrition.
Characteristics of Benign Tumors
Cohesive, slow/limited growth, well circumscribed, lobulated, encapsulated, mobile.
How can benign tumors be lethal?
If they’re in very sensitive areas like the heart (atrial myxoma) or the brain (meningioma).
Characteristics of malignant tumors
Aggressive and limitless growth, invasion/destruction of adjacent structures, poorly demarcated. Infiltrating borders.
How are neoplasms named?
Named for the tissue they are becoming, or for the tissue from which they are derived.
Leiomyoma, and cancerous equivalent
Smooth muscle benign tumor. Leiomyosarcoma.
Adenoma and cancerous equivalent
Glandular epithelium benign tumor, adenocarcinoma.
Hamartoma
Disorganized growth of indigenous tissue. Ex: disorganized bile ducts in the liver
Choristoma
Normal architecture in the wrong location, happens during development. Ex: heterotopic pancreas in the stomach.
Parenchyma vs Stroma
P: The tumor. S: supporting cells and connective tissue.
Hyperplasia
Increase in the number of cells.
Metaplasia
Replacement of one mature cell type with another. Ex: Columnar to squamous in the lungs of smokers.
Dysplasia
Loss of cell uniformity and orientation. Generally with epithelium, where the cells grow in number. First sign on way to malignant neoplasm.
Desmoplasia
A collagenous fibrosis reaction to invasion.
Anaplasia
Complete lack of differentiation. Certainly a malignancy.