Neoplasm- Dr. Fischer Flashcards
Two basic components of tumors
Tumor parenchyma
Reactive stroma
Tumor parenchyma
neoplastic cells
reactive stroma
- Connective tissue, includes fibrous tissue, blood vessels and inflammatory cells
- In many malignant tumors connective tissue contains abundant collagen and is firm: Desmoplasia (desmoplastic stroma)
Fibrous tissue benign
fribroma
adipose tissue benign
lipoma
cartilage benign
chondroma
bone benign
osteoma
blood vessels benign
hemangioma
lymph vessels bengin
lymphangioma
smooth muscle benign
leiomyoma
striated muscle bengin
rhabdomyoma
fibrous tissue malignant
fibrosarcoma
adipose tissue malignant
liposarcoma
cartilage malignant
chondrosarcoma
bone malignant
osteosarcoma
blood vessels malignant
angiosarcoma
lymph vessels malignant
lymphangiosarcom
smooth muscle malignant
leiomyosarcoma
striated muscle malignant
rhabdomyosarcoma
benign tumors from glands
adenoma
benign epithelial that make fingerlike projections
papilloma
benign cystic masses
cystadenoma
benign projections above mucosal surface
polyp
malignant tumors from glands
adenocarcinoma
malignant squamous epithelium
squamous cell carcinoma
malignant kidney cells
renal cell carcinoma
malignant liver cells
hepatocellular carcinoma
fibroadenoma
- benign neoplasm of breast
- biphasic: derived from fibroblasts and glandular tissue
teratoma
- tumor arising from totipotent germ cells in testis or ovaries
- can form somatic tissues derived from all three germ layers
seminoma
in testis
local invasion types
- Benign: circumscribed
- malignant: infiltrative, locally invasive
well differentiated
tumor closely resembles original tissue
poorly differentiated
little or no resemblance to original tissue
anaplastic
no resemblance to original tissue
dysplasia
- Loss of architectural orientation
- Loss of uniformity
- Nuclear pleomorphism
- Large hyperchromatic nuclei with high nuclear to cytoplasm ratio
- Disordered growth
- Most common in epithelial organs
- Can be precursor lesion to invasive cancer
- Dysplasia: intact BM
- Invasive cancer: breach
Rate of growth and proliferation
- Benign usually slow, malignant usually fast → not reliable predictor
- Tumor necrosis is feature of malignant tumors
- Rapidly growing cancers may outgrow blood supply and cause ischemia and tumor necrosis
Metastatic cascasde
- Cells cross BM and invade vessel
- Can travel in bloodstream, lymph, and along nerves
- Colon cancer likes to metastasize to the liver
once cells acquire enough damage to leave and become malignant
- loss of e-cadherins
- loss of contact and communication
- degrade underlying matrix (collagenases and can release GF)
- use different set of integrins to adhere and migrate and invade
EPITHELIAL-MESENCHYMAL TRANSITION (EMT)
- To acquire motility and invasiveness cancer cells increase and decrease gene expression
- Downregulate epithelial markers (e-cadherin)
- Increase mesenchymal markers like vimentin and smooth muscle actin
- Favors pro-migratory phenotype
- SNAIL and TWIST transcription factors (Repressors for e-cadherin)
SEED AND SOIL
Many tumors arrest in first capillary bed they encounter
Primary tumors preferentially metastasize to certain sites
- Colon carcinoma to liver
- Prostate carcinoma to bone
- Lung cancer to adrenal glands
Organ tropism of cancer
- Endothelial cells at metastatic sites may express adhesion molecules or chemokines
- Microenvironment may express chemokines that attract cancer cells
tumor microenvironment components
Cancer cells Cancer associated fibroblasts Pericytes Endothelial Tumor promoting inflammatory cells Extracellular matrix
Tumor microenvironment makes use of
Proteases TGF-beta HGF PDGF VEGF Ang-1 Etc
