NEOPLASIA Flashcards
neoplasia
NEOPLASIA – means “new growth”.
• TUMOUR – a term previously applied to a swelling caused by inflammation. The nonneoplastic meaning has vanished and TUMOUR=NEOPLASM in current medical
practice.
neoplasm in eras(definitions)
NEOPLASMPre-molecular Era:
• An abnormal mass of tissue, the growth of which exceeds and is
uncoordinated with that of normal tissue, and persists in the
same excessive manner after the cessation of the stimulus
which evoked the change.
Modern Era:
• Disorder of cell growth triggered by a series of acquired
mutations affecting a single cell and its clonal progeny
oncology
- Study of tumours or neoplasms.
- More oriented towards treatment of neoplasia
- BENIGN NEOPLASMS
- Gross and microscopic appearance appears ‘innocent’.
- Remains localised; cannot spread to other sites.
- Amenable to surgical removal; patient generally survives
malignant neoplasm
MALIGNANT NEOPLASMS
Capable of invasive and destructive growth.
Can metastasise (i.e. spread to distant sites).
hermatoma
Malformation comprising cells which are resident in the organ, but demonstrate
disorganised growth.
dysplasia
• Literally means “disordered growth.”
• Encountered principally in epithelia and is characterized by a
constellation of changes that include a loss in the uniformity of the
individual cells as well as a loss in their architectural orientation
differentiation
• Degree to which tumour cells histologically resemble the cell or tissue
of origin.
• Well-differentiated tumour cells look more like normal cells; tend to
grow and spread more slowly than poorly differentiated or
undifferentiated tumour cells.
• Differentiation is used in tumour grading systems for malignant
tumours.
anaplasia
• Lacking differentiation
• A tumour that defies accurate classification is designated as
anaplastic and such tumours are always malignant.
invasion
• The tendency of tumour cells to breach their basement membrane,
spread beyond the layer of tissue in which they developed growing
into surrounding, healthy tissues.
• Also called infiltration.
tumour nomeclature
The specific name of an individual tumour invariably ends in the suffix
‘-oma’.
• Relics of this suffix’s former wider usage remain, as in ‘granuloma’
(an inflammatory aggregate of epithelioid macrophages),
‘tuberculoma’ (the caseating lesion of tuberculosis), ‘atheroma’ (lipidrich intimal deposits in arteries), and ‘mycetoma’ (a fungal mass
populating a lung cavity) and ‘haematoma’ (mass of coagulated
blood), these are not neoplasms.
• NB: Tumour previously denoted just any abnormal swelling.
histogenic classification
• Histogenesis – the specific cell of origin of an individual tumor, determined
by histological examination and specifies the tumour type. This is
incorporated into the tumor name e.g. squamous cell carcinoma
- From epithelial cells
- From connective tissue
- From lymphoid and hematopoietic organs
epithelial tumours
• Named histogenetically according to their specific epithelial type and
behaviourally as benign or malignant.
• Benign epithelial tumours are either:
• papillomas- tumour of non-glandular or non-secretory epithelium such
as transitional epithelium or stratified squamous epithelium.
• adenomas- tumour of glandular or secretory epithelium.
malignant tumour
alignant epithelial tumours are always called carcinomas.
• Carcinomas of non-glandular epithelium are always prefixed by the
name of the epithelial cell type e.g. squamous cell carcinoma and
transitional cell carcinoma.
• Malignant tumours of glandular epithelium are always called
“adenocarcinomas’’
RENAL CELL CARCINOMA
Typical crosssection of yellowish, spherical neoplasm in one pole of the kidney.
Adenocarcinoma
Adeno-Glandular epithelium
carcinoma-Malignant epithelial neoplasm
mesenchymal neoplasm
Benign Smooth Muscle-Leiomyoma Skeletal Muscle-Rhabdomyoma Fat-Lipoma Cartilage-Chondroma Blood vessels-Hemangioma Bone-Osteosarcoma
Malignant Smooth muscle- Leiomyosarcoma Fat-Liposarcoma skeletal muscle-Rhabdomyosarcoma cartilage-Chondrosarcoma blood vessels- Angiosarcoma
HAEMATOLYMPHOID NEOPLASMS
benign
N/A
Malignant
Hematopoietic cells- Leukemia
Lymphoid cells - Lymphoma
MIXED TUMOURS (usually derived from 1 germ cell layer)
benign
Salivary gland-Pleomorphic adenoma
Malignant
salivary gland- malignant mixed
tumour of salivary gland origin
Renal anlage - Wilms tumour
Germ cell neoplasms
Cell of Origin Benign Malignant benign Germ cell- Mature Teratoma Dermoid cyst Malignant germ cell : 1 malignant Teratoma 2.Teratocarcinoma
Embryonal tumours (blastoma)
• Usually in those below 5 years of age, resembles embryonic form of
organ it arises from.
Malignant
Kidney- Nephroblastoma
Liver- Hepatoblastoma
Eye -Retinoblastoma
Adrenal -Neuroblastoma
BEHAVIOURAL CLASSIFICATION
- Benign
* Malignant
Benign Neoplasms
• Non-invasive and remains localised.
• Slow growth rate.
• Close histological resemblance to parent tissue.
• Clinical Features
• Pressure on adjacent tissue (meningiomas → epilepsy).
• Obstruction of the flow of fluid (duct obstruction).
• Production of hormone (benign thyroid tumour -thyrotoxicosis).
• Transformation into malignant neoplasm (adenomatous polyp to
adenocarcinoma).
• Anxiety (fear that lesion may be something more sinister).
Malignant Neoplasms
- Relatively rapid growth rate.
- Variable histological resemblance to the parent tissue.
- Poorly circumscribed.
- Invasive growth.
- Encroach on & destroy adjacent tissues.
- Central necrosis (outgrow blood supply).
- Metastasize
DIFFERENCES BETWEEN BENIGN AND MALIGNANT NEOPLASMS
Benign
Differentiation/Anaplasia: Well-differentiated (anaplastic)
Rate of Growth: Progressive and slow;May regress; Mitotic figures rare and normal
Local Invasion: Usually circumscribed and encapsulated
Metastasis: Absent
Malignant
differentiation/Anaplasia: Less well differentiated or completely undifferentiated
rate of growth: Erratic, but generally rapid; Mitotic figures may be numerous and abnormal
Local invasion: Poorly circumscribed and locally invasive
Metastasis: Frequent
