Pathology -carcinogenesis ; Cancer Flashcards
What is carcinogenesis?
Transformation of normal to neoplastic cells through permanent mutation
What 3 things describe a neoplasm?
Autonomous, abnormal, persistent new growth
What can a neoplasm only arise from?
A nucleated cell
Can’t arise from erythrocytes but can from their precursor (erythroblasts)
What is a tumour?
Any abnormal swelling
Eg, neoplasm, inflammation, hypertrophy, hyperplasia
What do solid tumours consist of ?
Neoplastic cells and stroma
What are 2 ways tumours are classified by?
Behaviour (benign or malignant)
Histogenesis
Benign vs malignant
Invading?
Rate of growth?
Spread?
Differentiation?
Benign:
Localized (No BM invasion)
Slow growing (little mitosis figures)
Well circumcised
Exophytic (outward growth)
Encapsulated
Rare ulceration & necrosis
Close resemblance to normal tissue
Non invasive (doesn’t spread)
Malignant:
BM invading
Very fast mitosis growth (hyper dense nuclei) -stain dark
Invasive - form metastases
Endophytic - inward growth
Common necrosis & ulceration
Poorly differentiated (little resemblance to normal tissue)
How can benign structures still be pathological?
Pressure on local structures - pituitary chiasm
Obstruction
Production of hormones (prolactinoma)
Transformation —> malignant
Anxiety and stress
What is histogenesis?
Origin cell of tumour
Epithelial cells:what are they called?
Non glandular benign
Non glandular malignant
Glandular benign
Glandular malignant
Papilloma
Carcinoma
Adenoma
Adenocarcinoma
Connective tissue (sarcoma) : benign & malignant
Adipocytes
Muscle (striated)
Muscle (smooth)
Cartilage
Bone
Lipoma, liposarcoma
Rhabdomyoma, rhabdomyosarcoma
Leiomyoma, leiomyosarcoma
Chondroma, chondrosarcoma
Osteoma, osteosarcoma
Lymphoid:
What are they always?
Leukemia
Lymphoma
(Always malignant)
A basal cell carcinoma…
Never metastasize
What are:
Melanomas
Mesotheliomas
Teratoma
Melanocyte malignancy
Mesothelial malignancy-typically pleural
Cancer of all 3 embryonic germ layers
What are these 3 ?
Burkitt’s lymphoma
Kaposi sarcoma
Ewing sarcoma
B cell malignancy caused by EBV
Vascular endothelial malignancy, HIV associated
A bone malignancy
Tumours are graded based on?
Similarity to parent cell
how are the tumours graded based on similarity to parent cell?
- Well differentiated (>75% cells resemble parent)
- 10-75%
- Poorly differentiated (<10% cells resemble parent)
4 Characteristics of the neoplastic cell?
Autocrine growth stimulation - over expression of growth factor and mutation of tumour suppressor genes eg. P53 and under expression of growth inhibitors
Evasion of apoptosis
Telomerase; prevents telomeres shortening with each replication (this normally rate limits the extent of mitosis a single cell can undergo)
Sustained angiogenesis + ability to invade BM
Classes of carcinogens (cancer causing agents) & examples
Chemical - eg. Paints, dyes, rubber, soot
Viruses - EBV (burkitt’s), HPV (cervical cancer)
Ionizing + non ionizing radiation - UVB in skin cancer
Hormones, parasites, mycotoxins- eg, increased oestrogen implicated in breast cancer
MISC - eg, asbestos
Pathways of metastasis (5 steps)
- Detachment (from 1^ )
- Invasion of other tissue
- Invasion of BV
- Evasion of host defense, adherence to BV wall
- Extravasation to distant site
What are the 3 methods of spread?
Haematogenous
Lymphatic
Transcolemic
What is haematogenous spread?
Key point?
Via blood (go to bone,breast, lung, liver)
KEY POINT: 5 main metastasis to bone = BLT KP
Breast, Lung, Thyroid, Kidney, Prostate
What is lymphatic spread?
2^ formation in lymph nodes
Eg. Lymphoma (rubbery lymphadenopathy)
What is transcolemic spread?
Via exudative fluid accumulation, spread through pleural, pericardial + peritoneal effusions
How are sarcomas and carcinomas mostly spread?
Sarcomas - mostly haematogenous
Carcinoma- mostly lymphatic
What are exceptions to how carcinomas are spread?
Follicular thyroid
Chanocarcinoma
RCC
HCC
ft CRH
How are tumours staged?
Mostly TNM
Tumour, node, metastasis
What is tumour staging different for?
Eg?
Leukemias, lymphomas, CNS cancers
Eg. Lymphoma - ANN ARBOUR 1-4, A or B
What are the 2 mutations involved in colorectal cancer called?
FAP (familial adenomatous polyposis)
HNPCC (lynch syndrome)
What is FAP (familial adenomatous polyposis)?
Autosomal dominant gene, mutated, APC gene (adenomatous polyposis coli)
Millions of colorectal adenomas
Inevitable adenocarcinoma by 35 y/o
What is HNPCC? (Lynch syndrome)
Mutated MSH gene, autosomal dominant
This genes involved in DNA mismatch repair
What is screening?
What type of screening is cancer screening?
Method of early detection
2^ prevention , making management easy
Which 3 cancers are screened for in the UK and how?
Cervical (cervical swab)
Breast (mammogram)
Colorectal (fecal occult - fecal immuno histochemical test)
What test is done at birth and what does it test for?
Heel prick test at birth for sickle cell, CF, hypothyroid
