Malignant tumor
•
Cancer from mesenchymal
tissues
•
- sarcomas
•
Fibrosarcomas
•
Liposarcomas
•
Leiomyosarcmas
•
Epithelial cell origin –
carcinomas
•
Adenocarcinoma
•
Squamous cell carcinoma
Characteristics
of benign and malignant
•
1. degree of differentiation
and anaplasia
•
2. rate of growth
•
3. local invasion
•
4. Metastasis
Differentiation
•
Extent to which parenchymal
cells resemble comparable normal cells
•
Well differentiated –
resemb;ling mature normal cells
•
Poorly differentiated –
primtive looking,
unspecialized
cells
•
All benign tumors are well
diffrentiated
Malignant
tumors
•
Range from well
differentiated to undiffrentiated
•
Undiffrentiated – pleomorphic,hyperchromatic
•
Large nuclei – 1:1 instead
of 1:4 1:6 ratio
Rate
of growth
•
Slow – benign
•
Cancer – fast, erratic
•
Generally proportionate to
their level of differentiation
Local
invasion
•
Benign tumors grow as cohesive expansile masses and remain localized
- don’t have the capacity to infiltrate
invade or metastasize to distant sites
Cancers grow by progressive infiltration, invasion, and destruction of the
surrounding tissue
- poorly demarcated
Metastasis
•
Tumor implants away from the
primary tumor
•
Implies malignant growth
•
benign tumor do not
metastasize
Pathway
of spread
•
Seeding cavities and
surfaces
•
Lymphatic spread
•
Hematogenous spread
Grading
and staging for cancer
•
Grading is based on degree of differentiation
•
Grades 1 – 4 on degree of
anaplasia
•
Staging is based on size of primary tumor
•
extentent of spread to lymph node
•
presence
or absence of metastasis
•
TNM classification
