Neoplasia
A proliferation of a clone of cells that have been "transformed" and acquired some interesting traits: Autonomy, Non-equilibrium of growth, Independent of initiating stimulus, No real adaptive value to host, Can be benign or malignant.
NOT inflammatory tu
Epithelium
The layer of cells covering the inner and outer surfaces of the body. Ex. Squamous (skin), colonic (colon), outpouchings (sweat glands, crypts, etc.).
Mesenchyme
The connective tissue that holds stuff together (blood vessels, collagen, fat, muscle, etc.).
Mucosa
Lining of internal organs - gastrointestinal, urogenital, pulmonary. Made of epithelium, outpouchings, and mesenchyme.
Parenchyma
Neoplastic cells making up the important part of the tumor (but can also apply to normal tissue - ex. Hepatocytes that make up liver)
Stroma
Surrounds parenchyma; NON-neoplastic but reactive in response to neoplasm, e.g. tries to localize parenchyma, provide nutrients for parenchyma. Ex. Inflammatory cells, blood vessels around tumors.
Differentiation
degree to which cell/tissue resembles its normal counterpart (Well = normal tissue; worst = no hint of normal cell type at all/ hard to tell what kind of tumor).
Benign tumor
Differentiation
: well-differentiated; may strongly resemble tissue of origin.
Growth rate
: slow growing; can occasionally regress; few, normal mitoses.
Local aggression
: usually well-demarcated; respect borders.
Metastasis
: No
Pleomorphic
Variation in size and shape. Opposite of monomorphism
Malignant tumor
Differentiation
: Less differentiation; possble anaplasia; atypical architecture.
Growth rate
: more erratic growth; may rapidly progress; more mitoses (abnormal shapes)
Local aggression
: Often ignore borders; infiltrate adjacent structures.
Metastasis
:
Metastasis
**hallmark of malignant tumors! Discontiguous spread of tumor that travels via lymph or vascular channels, even sometimes surface-to-surface.
Tumor cells may travel basically anywhere and take up residence...
- Lymph nodes
- Other tissues (like lung, live
Euplasia
Good, normal growth
Aplasia
lack of growth; primordium present (fetal-like tissue)
Agenesis
no tissue, no primordium
Hyperplasia
normal cells but too many; cell division. Ex. Callouses on hands
- Hormonal - lactating breast
- Compensatory - Responding to an "insult
Hypoplasia
Less than normal number of tissue cells
Hypertrophy
each cell gets bigger, e.g. heart
Carcinogen
'helps' development of cancer, e.g. genetic changes, injury; MULTI -step process- not just one hit; EX: chemicals, radiation, and certain viruses etc.
Metaplasia
1 normal tissue/cell type is changed into another normal cell type population; cell division PLUS altered gene expression; one possible response to injury (ex. Barrett's esophagus)
Dysplasia
Description
: A morphologic alteration in both cytology (microscopic appearance) and arrangement of epithelial cells. The individual cells not only look abnormal, they do not relate to each other in a normal fashion and do not mature normally
Hallmarks
:
Anaplasia
backward growth" (no differentiation or morphological distinguishing features; very pleomorphic)
Polyp
A visible projection of a neoplasm above mucosa
- Benign or malignant
- Projects into the lumen (i.e., the empty space inside) of some organ, like the gastrointestinal tract
Architecture
- Pedunculated: standing up on a stalk (like a mushroom)
- Sessile:
Desmoplasia
reactive fibrous tissue (stroma) growing around malignant neoplasm; microscopically seen ? clue for malignancy
Carcinoma-in-situ
epithelial neoplasm w/ malignant potential that hasn't become invasive; on the cusp of invasion!
Hamartoma
A mass of cells that are of the types indigenous to the particular tissue in which they are found but are abnormally arranged or jumbled.
Choristoma
A nest or mass of ectopic tissue that is histologically normal but is growing in an abnormal location.
An "embryologic accident"
Pictured: Pancreatic tissue in the wall of the stomach (= "pancreatic heterotopia").
NOT the same as metastasis
Lymphoma
tumor of malignant lymphocytes
Clonal
Tumor cells are _____. (whole population came from ONE cell; genetically identical); Greek word for these is Oncos; All of these are not tumors. Overtime mutations build up that can add genetic diversity.
Pleomorphic
Malignant tumors composed of ____ cells
Non-existant
Benign counterparts to lymphoma are...
Adenoma
Epithelium tumor; implies "glands", some GI polyps are this.
Fibroma
Tumor in fibrous tissue
Chondroma
Tumor in the cartilage
Leiomyoma
Tumor in the smooth muscle
Teratoma (1?)
Multiple (mature) tissue types - from totipotent (germ) cells
Carcinoma
Epithelial cancer; metastatic potential; subclassified by type of skin cell (ex. Squamous cell carcinoma)
Sarcoma
Mesenchymal cancer; less commonly metastasize, but very locally aggressive and recur frequently
Teratoma (2?)
Multiple (immature) tissue types, regressed in a way. Unable to become mature.
Nevus
Mole or tumor of melanocyte
Metaplasia v dysplasia
Metaplastic epithelium does not inevitably become dysplastic...but it may.
Dysplastic epithelium can also arise de novo without pre-existing metaplasia.
Dysplastic epithelium does not inevitably become an invasive cancer...but it may.
Severe (= "high grad
Grade of malignancy
Based on degree of differentiation
How closely the neoplasm resembles the "tissue of origin"
- Well differentiated
- Moderately differentiated
- Poorly differentiated
- Undifferentiated/Anaplastic
Grade often predicts degree of aggressiveness.
Note: subje
Stage of malignancy
This is assessment that details how far advanced the malignancy is in a particular patient. (Think S for Spread)
Takes into account:
- Size
- Depth
- Lymph node metastasis
- Distant metastasis
TNM Classification
T
umor
N
odes
M
etastasis