Apporach to cancer Flashcards
what is cancer?
an uncontrolled proliferation of cells independent of the normal requirement for new cells
do cancers spontaneously resolve?
no
what are the AVMAs signs of cancer?
abnormal swelling that persists or continues to grow
sores that don’t heal
unexplained weight loss
loss of appetite
bleeding/discharge from body opening
bad odour (especially mouth)
difficulty eating/swallowing
reluctancy to exercise
difficulty breathing, urinating, defecating
change in behaviour
what should be done when examining a mass?
record size, shape and location of lesion
assess invasiveness and attachment to underlying tissue
look for characteristics of malignancy
what cancer is haematology useful for diagnosing?
leukaemia
what is cytology used for in cancer cases?
guiding diagnostics and treatment prior to surgery
what is histopathology used for in cancer cases?
making a final diagnosis and guiding post-surgical treatments
when doing a FNA what tips would you give someone?
don’t go through the lesion (can get seeding)
vigorous in multiple directions
cover needle hub when withdrawing
what are the best things to sample using needle off FNA?
lymph nodes
suspected round cell tumours
(exfoliate well)
what are the contraindications of FNA sampling?
bleeding (check coagulopathy/platelets)
risk of pneumothorax, urine/abscess leakage
tumour transplanting into deeper tissue
what is the risk of FNA sampling the chest?
pneumothorax
what are some cases which direct impression smears are useful for?
intra-operative or post-mortem samples
ulcerative superficial lesions
nasal biopsies
airway lesions
what are the issues with FNA?
not always diagnostic (20% aren’t)
can be non-representative sample (take multiple samples)
what are some tissue biopsy techniques?
needle core biopsy
incisional biopsy
surface/pinch biopsy
punch biopsy
excision biopsy
what are the risks of taking a biopsy of cancer?
haemorrhage
transplantation of tumours
compromise future surgery
damage to adjacent tissue
what are the advantages of needle core biopsy?
larger sample than an aspirate (some architecture)
inaccessible tissues can be sampled percutaneously
multiple samples easily taken
superficial biopsies can be sampled under sedation
what is a needle core biopsy also known as?
trucut
how should a needle core biopsy be removed from the needle?
flush with saline (don’t shake because the architecture will break up)
what is the main risk of bone core biopsies?
damaging cortex which could lead to a pathological fracture
what is an incisional biopsy?
surgical removal of a segment of solid tissue
what is the most common incisional biopsy used?
wedge
what are the advantages of incisional biopsy?
good architecture evaluation
can do histopathological grading
can select the sample taking
more tissue to carry out diagnostics on
what are the disadvantages of incisional biopsy?
GA required
time/cost
regarding the position of an incisional biopsy, where should it be?
in a position that the entire tract can be removed during subsequent surgery
what are some structure that a pinch biopsy can be used for?
respiratory, GI, urogenital tracts
what needs to be done before taking a pinch biopsy of the nasal tract?
radiograph and measure how far in to put your instruments (don’t go beyond cribriform plate)
what should be done when taking a punch biopsy to reduce the artefacts?
only rotate in one direction
what is an excision biopsy?
removal of the extirpation of a lesion or mass followed by removal of biopsies from it for histopathological evaluation
what cases can excision biopsies be used in the absence of pre-treatment diagnosis?
haemorrhaging splenic mass
mammary tumours
pulmonary tumours
what should be done before excision biopsies? (in most cases)
staging
what are some contraindications for using excision biopsies for the skin/subcutaneous masses?
rapidly growing
poorly demarcated
peritumoural oedema/erythema
skin ulceration
injection site masses in cats
suspicion of MCT or STS
non-diagnostic FNAs
