Neoplasia Flashcards
Define neoplasia
According to british oncologist willis a neoplasm is an abnormal mass of tissue the growth of which exceeds and is uncoordinated with that of normal tissues and persists in the same excessive manner after cessation of the stimulus which evoked the change.
Classofy neoplasia
On the basis of tissue of origin
Composed of one parenchymal cell type
Fibroma fibrosarcoma
Lipoma liposarcoma
Osteoma osteogenic sarcoma
Chondroma chondrosarcoma
Hemangioma angiosarcoma
Rhabdoma rhabdomyosarcoma
Adenoma adenocarcinoma
Nevus malignant melanoma
More than one neoplastic cell type usually derived from more than one germ cell layer
Salivary gland
Pleomorphic adenoma
Malignant mixed tumor of salivary gland origin
More than one neoplastic cell type derived from more than one germ cell layer
Totipotential cells in gonads
Dermoid cyst. teratocarcinoma
Name some childhood tumors
Leukemia
Retinoblastoma
Neuroblastoma
Wilms tumor
Hepatoblastoma
Locally malignant tumors
Tumors which are locally invasive but show little to no tendency to metastasize
Basal cell carcinoma
Giant cell tumor of bone
Glioma
Fibromatosis
Craniopharyngioma
Mixed salivary gland tumor
Features of anaplasia
1.Pleomorphism
2.Abnormal nuclear morphology ie nuclei are hyperchromatic and large in relation to cell
Nucleus to cytoplasm ratio is 1:1
Chromatin is coarsely clumped and distributed along nuclear membrane
3.Large central areas undergo ischemic necrosis
4.Loss of polarity
5.Mitosis
Define pappiloma
Benign epithelial neoplasm producing microscopically or macroscopically visible finger like or warty projections from epithelial surfaces
Polyp and types
Benign or malignant neoplasm produces a macroscopically visible projection above a mucosal surface called a polyp
Types: 1.neoplastic polyp eg adebomatous polyp of colon
Polypoid carcinomas of git
Benign mesenchymal tumors like lipoma hemangioma
2. Non neoplastic polyp.
Inflammatory
Hyperplastic
Hamartomatous
3. Malignant polyp: polypoid cancer
Define dysplasia with features
Dysplasia means disordered growth which is characterised by a loss of uniformity of indivisual cells as well as a loss in their architectural orientation
Characters
Pleomorphism of cells and nuclei
Large hyperchromatic nucleus with high nucleus cytoplasmic ratio1:4- 1:6
Nuclear shape is variable with irregular margin
Coarsely clumped chromatindistributed along nuclear membrane
Abundant mitotic figures
Size and number of nucleoli increase
Disordered tissue architecture
Differentiation
Refers to the extent to which neoplastic cells can resemble the comparable normal cells both morphologically and functionally
Characteristics of benign and malignant neoplasm
Differentiation and anaplasia
Rate of growth
Local invasion
Metastasis
Metastases
These are tumor implants discontinuous with primary tumor
1. Benign tumors do not metastasize
2. Malignant tumors all can metastasize except locally malignant tumors
What are the different routes of metastasis
Direct seeding of body cavities or surfaces
Lymphatic spread
Hematogenous spread
How malignant tumor spreads in body
Local invasion
Metastasis
Skip metastasis
Local lymphnodes may be bypassed
Eg. Breast ca going to lateral axillary lymph node insteaf of apical lymph node
Causes: venous lymphatic anastamosis
Lymphatic channel obliteration
Sentinal lymph node
The first lymph node in a regional lymphatic basin that recieves lymph flow from primary tumor
It detects the spread of melanomas… colon ca etc
If metastasis is not present in this node it will not be present in other nodes
Henatogenous spread
Mainly venous spread
hcc
rcc
Prostatic ca
Rarely arterial
Dysplasia
Mild .. if changes are in lower 1/3rd
Moderate if changes are in lower 2/3rd
Severe if changes are present in whole layer of epithelium
Carcinoma in situ
When dysplasia is severe and involves full thickness of epithelium but lesion does not penetrate the basement membrane.
Eg. Cervical intraepithelial neoplasm grade 3
Ca insitu in the epidermis of skin
In situ carcinomas of female breast, urinary bladder
Carcinogen
Agents that cause genetic damage and induce neoplastic transformation of cells
Classify carcinogens
1.Chemical carcinogens
a.Directly acting - alkylating agents
Acylating agents
b.Indirectly acting- procarcinogens
c.Naturally occuring eg .
aflatoxin b1
Others
2. Radiant energy:
uv rays
IR
3. Microbial carcinogens
.oncogenic virus: dna -
hbv, ebv , hpv, mcpv, kshv
Rna- htlv1, hcv
Bacteria- helicobacter pylori causes gastric carcinoma, gastric lymphoma
Peptic ulcer
3. Parasites: s. hematobium: bladder ca
In which tumor hcg is present
Choriocarcinoma
