Pathology of cancer Flashcards
Histopathological assessment important for
- Diagnosis - tissue confirmation is needed to know whether to diagnose cancer or not
- tissue for subtyping the cancer
- need to understand terms used in pathology reports- Prognosis e.g. Tumour grading and staging
- Treatment e.g. Surgical resection, chemotherapy, radiotherapy
- Additional ancillary tests e.g. Molecular testing for prediction of chemo/immunotherapy
What is meant by neoplasm
is a mass of cells
Neoplasm literally means “new growth”
- they have undergone an irreversible change from normlaity
- proliferate without any signal to stop them
- they are partially and completely independent of factors that control normal cell growth
- doesn’t have signals to tell it to stop, so it grows and multiples
Definition of cancer
A malignant neoplasm
How do we classify neoplasm
- behaviour
- is it benign or malignant
- histogenesis
- where it came from
- histological cells
- subtyping within tissue
- squamous → carcinomas, glanduar → adenocarcinomas
- within different tissues, you can have different types of cancers
- this is important because they all have differently
- subtyping within tissue
- functional: hormone secretion
Classification of neoplasm
How can maligant neoplasms behave
like what can they do
- Local invasion into surrounding tissue
- Spread to distant sites to form secondary deposits (metastases).
Classification of neoplasm
How can neoplasms metastise
Metastasis occurs via two main routes (lymphatic and haematogenous via venous channels )
Classification of neoplasm
What is meant by the phrase neoplasms can behave in an intermediate way
invades local tissues but does not metastise
e.g basal cell carcinoma of the skin
Classification of neoplasm
Epithelial
what do we call them, where do they line, are thet malignant
name: carcinoma
tissues: skin, lung, gastrointestinal tract
maliganancy: most epithelial tissues are malignant
Classification of neoplasm
Mesenchymal tissues
what do we call them, where do they line, are thet malignant
name: - if bengin tumor from soft soft tissue “lipoma”, muscle “leiomyoma”, blood vessels “ haemangioma”
- If malignant termed “ sarcoma”
tissues: bone, cartilage, bone marrow stroma, interstitial fibrous tissue, skeletal muscle,
maliganancy: typically benign neoplasms but if malignant called sarcoma
Classification of neoplasm
What are Haemato-lymphoid neoplasms called
lymphoma
Classification of neoplasm
If a cancer is involves blood cells, what is it called?
leukaemia
Classification of neoplasm
What are germ cell neoplams called
teratoma, seminoma
Classification of neoplasm
What is meant by ifferentiation
- the degree to which neoplasm resembles its tissue or origin
- begin
- well-differentiated looks similar to the parent cell
- malignant
- differentiation is variable
- can look like parent cell or look nothing like it
- differentiation is variable
How do we grade differenation
Grades 1-3
well differeniated to poorly
Why is knowing tumor differeniation important
- Poorly differentiated cancers behave more aggressively
- Well-differentiated cancers have better prognoses and certain well-differentiated cancer
- for example, prostate can be managed conservatively
- Some malignant tumours are so poorly differentiated hard to determine their histogenesis
if its hard to determine what cell the cancer came from what is it called
called ANAPLASTIC.
What is a begnign cancer from glandular tissue called
adenocarcionma
Classofication
Tertorma
where do they come from
- comes from embryonic germ cells
- comes from all three germ cell layers
- ectoderm
- mesoderm
- endoderm
- comes from all three germ cell layers
Where do Teratomas occur
- Ovary - usually benign
- Testis - usually malignant
- Midline structures - behaviour variable (retroperitoneum, mediastinum)
can find hair, teeth, repsortory lining, skeletal muscle, skin
Compare gross apperance of neoplasms
begnin bold, maligant normal
Shape: well circumsised/irregular
size: generally smaller can be MASSIVE/generally larger
haemmorhage: unusual/common
ulceration: unusual/common
necrosis: unusual/common
Difference in begnin and malignant nuclei
benign: normal
maliganant: massive
nuceloi more promianat in maligant
maligant cells vary in size loss of polarity,
Difference in growth of B and M
Speed: Slow/rapid
spontenous arrest: common/rare
Types of bioposes
- endoscopic biopsies (e.g. upper & lower GI tract, bronchus)
- needle biopsies (radiologically guided)
- punch biopsies (skin)
How can we get cytology specimens
- smears (e.g. cervical)
- endoscopic brushings
- body fluids (e.g. sputum, urine, effusion fluids)
- fine needle aspiration specimens
cytology is quick and cheap to obtain diagnosis
Limiations of bioposy
- tumour heterogeneity
- may not be repsenstive of the whole tumor
- targeting lesions may be hard because they are
- small lesions
- inaccessible
- surrounding stromal reaction
Why is cytology good
- ess invasive
- bladder cancer→ urine
- fine needle
- stick into mass
- and then sent to pathology
- smaller tissue samples provided
- cells, instead of groups
- problem: may be hard to interpret compared to a biopsy
- cells, instead of groups
Why do we do bioposies or cytology
– Confirm the diagnosis of malignancy
– Determine the aggressiveness of a tumour (histological grade)
– Assess the extent of spread (histological stage)
– Examine completeness of excision.
What do we need to look at macroscopically
about tumor
- Size
- Shape (well-circumscribed or irregular).
- Extent of local spread.
- Proximity to surgical resection margins.
- Identification of lymph nodes (important for staging).
- Other macroscopic features where relevant (e.g. colour, haemorrhage, necrosis).
What do we know about tumor microscopically
- Confirms ( or establishes) a diagnosis of cancer.
- Other features that are assessed microscopically include the following:
- Histological type (e.g. glandular, squamous).
- Degree of differentiation (histological grade).
- Frequency of mitoses.
- Local invasion.
- Presence is important in determining a diagnosis of malignancy (e.g. capsular invasion in follicular carcinoma of the thyroid gland or hepatocellular carcinoma).
- Extent is important in staging.
- Vascular invasion.
- Examination of lymph nodes (for metastases).
This decides treatment after surgery
What is immunohistochemistry
how does it work, and use
What?
method of detecting the presence of specific proteins in cells or tissues.
How?
An antibody for each antigen. (epithelial - cytokeratin, lymphoid
Use?
Can help subtype and diagnose
- can also help for prognostic markers
- like markers of cell turnover
can be used for therapeutic options
- specific antigen markers used to idnentuy tumors that are likely to be good with the specific therapies tareggting that specific antibody
- e.g breast carcinomas expressing the growth factor HER2 can be treated with Herceptin.
What is molecular pathology
use + role
- gene mutation analysis; FISH; detection of specific translocations
- to support the diagnosis
- to predict response to targeted drugs (KIT in GIST; EGFR2 in breast adenocarcinoma; RAS in colorectal adenocarcinomas
Role of molecular biology
- diagnostic
- can diganose based on what translation or found etc
- progonsitic
- gilmoas with certain numbers like 1p, 19q LOH have a better prognosis
- predictive
