neoplasm 1 Flashcards
define neoplasia
- process of uncontrolled growth
- accumulation of cells due to proliferation or evasion of apoptosis
define neoplasm/tumor
- abnormal mass of tissue
- growth exceeds and is uncoordinated with normal tissue
- persists in same excessive manner after cessation of stimuli which evoked the changed
describe the features of neoplasms
- Progressive, PURPOSELESS, Pathological, proliferation of cells
- loss of control over cell division
- DNA damage at growth control genes (“checkpoints”) is central to development of neoplasm
- Carcinogens cause DNA damage and DNA damage leads to neoplasm
describe benign tumors
- neoplasm that grows without invading adjacent tissue/spreading to distant sites ( NO metastasis)
- usually well-circumscribed (with lack of invasion)
- generally amenable to local surgery
describe malignant tumors
- neoplasm that INVADES surrounding normal tissue
- usually spreads to distant sites (metastasis)
- may be treated successfully or can follow a deadly course
define intermediate tumors (local malignant)
- locally invasive - not bening
- no tendency for metastasis
define carcinoma in situ (dysplasia)
- pre-invasive cell proliferation
- cytological features of malignancy
describe parenchyma
- comprised of clonal neoplastic cells
- this determines its biologic behavior
- tumor derives its name based on the parenchymal component
- describe stroma
- comprised of connective tissue, blood vessels, macrophages and lymphocytes (tumor infiltrating lymphocytes, TILs)
- this determines the growth and evolution of tumor
- -> stroma scant = tumor soft and fleshy
- -> abundant collagenous stroma (desmoplasia) = stony hard (scirrhous)
describe the components of neoplasm
- Parenchyma = clonal neoplastic cells
- stroma = connective tissue, blood vessels, macrophages and lymphocytes
describe the nomenclature of benign tumurs and the exceptions
- add suffix -oma to proliferating cell type
- examples = fibroma, chondroma, osteoma
- EXCEPTIONS = melanoma and lymphoma, carcinoma
define cystadenomas
- adenomas with cavities or cysts
define polyp
- club-shaped growth
- benign epithelial tumor or hyperplasia
- tumor projects from mucosal surface into lumen of a hollow viscus
- benign epithelial tumors from surface lining - based on gross appearance
define papilloma
- benign epithelial tumors from surface lining - based on gross appearance
- benign tumors (squamous, transitional, ductal epithelium)
- PRODUCES FINGER-LIKE/WARTY projections from epithelial surfaces - branching pattern
- E.G. papilloma of urinary bladder, skin
Define Choristoma
- tumor like conditions
- ectopic rest of normal tissue
- normal tissue in a foeign location
- Example = rest of adrenal cells under kidney capsule, or in lungs or ovaries or pancreatic tissue in mucosa of stomach or small intestine
define Hamartoma
- tumor like condition
- non-neoplastic tumor-like lesion with disorganized and haphazard growth of tissues normally found at a given site.
- ex: pulmonary hamartoma = jumbled cartilage, bronchial epithelia and CT
describe general features of malignant tumors
- capsule generally absent
- rapid growth
- invasion present with metastatic potential
- atypical mitosis present
- well-differentiated or poorly diff
- suffix used = carcinoma/sarcoma
describe general features of benign tumors
- capsule generally present
- slow growth
- invasion absent, non-metastatic
- no atypical mitosis seen
- well-differentiated
- suffix used = oma
what is the cell origin of Sarcoma
- Mesenchymal origin
- initially spread via hematogenous
what is the cell origin of carcinoma
- epithelial cell origin
- spreads via lymphatics
define lymphoma
- cancer derived from lymph nodes or lymphoid tissue
- most are non-hodgkin’s lymphoma
- stomach is the most common extranodal site for a primary malignant lymphoma
define leukemia
- cancer derived from the bone marrow stem cells
- CLL is the most commona dult keukemia and overall leukemia
- ALL is the most common childhood leukemia and cancer
define teratoma
- tumor composed of more than one parenchymal cell type
- derived from MORE THAN ONE germ layer
- originates from totipotent cells (in gonads)
Define Peutz-Jeghers Syndrome
- Type of Hamartoma
- also called hereditary intestinal polyposis syndrome
- an autosomal dominant genetic disease
- characterized by the development of benign hamartomatous polyps in the GI tract + hyperpigmented macules (lips+ oral mucosa)
define monoconality
- origin of tumors from a single precursor cell
- All tumors (benign and malignant) are monoclonal
how do new subclones arise
- arise from the descendants of the original transformed cells by multiple mutations, BUT, all neoplasms arise from monoclonal population derived from a single cell
describe how to differentiate between a benign and malignant neoplasm
- differences based on appearance of tumor and behavior
- 4 criteria:
- -> rate of growth
- -> differentiation and anaplasia
- -> local invasion
- -> metastasis
