Approach to Investigation of Lymphadenopathy Flashcards
what can cause an enlarged lymph node (lymphadenopathy)
lymphoma
infection (viral/bacterial)
metastatic cancer (breast, ovary etc)
connective tissue disease (sarcoidosis, SLE etc)
swollen lymph node and night sweats indicate what causes?
lymphoma
infection
menopause
swollen lymph node and weight loss indicate what causes?
lymphoma
other malignancy
infection
what other symptoms might accompany swollen lymph node?
itch without rash
alcohol induced pain
fatigue
differentials for lymphadenopathy?
reactive bacterial infection viral infection metastatic malignancy lymphoma
approach to examining lymphadenopathy?
is it regional or generalised?
regional often from infection/abscess etc in specific site
features of lymphadenopathy from viral infection?
tender hard smooth skin not inflamed not tethered
features of lymph node in bacterial infection?
tender hard smooth skin inflamed can be tethered in some cases
features of lymph node in lymphoma
not tender rubbery/soft smooth skin not inflamed not tethered
features of lymph node in metastatic carcinoma?
not tender hard irregular skin not inflamed tethered
investigations if lymphoma or other malignancy is suspected in lymph node?
biopsy (core or FNA)
need a big sample to assess lesion architecture
does lymphoma show in CT?
no
what does lymph node biopsy allow?
exclusion of other causes (reactive etc)
classification of lymphoma which guides treatment etc
helps understanding of pathogenesis
how is lymph node pathology assessed on biopsy?
histology (microscopic appearance) immunohistochemistry of solid node immunophenotyping of blood/marrow genetics analysis molecular analysis
function of immunohistochemistry?
confirms lymphoma
subclassifys type of lymphoma
look at pattern of proteins on the surface of lymphoma cells and use antibodies against these
look at CD (cluster of designation) numbers
what does immunophenotyping do?
use cells in a liquid phase rather than block secretion of tissue (blood or bone marrow)
cells are tagged with antibodies attached to fluorochrome which emits a specific colour of light when laser shone on it
determine pattern on CD numbers
what is immunophenotyping best for?
leukaemias
lymphomas involving marrow (e.g Burkitt’s lymphoma)
what does cytogenetic analysis do?
specific patterns of chromosome abnormality in certain lymphomas
G banding (aspirate node > grow cells in culture > look at spread of chromosomes)
FISH (looks for specific abnormalities in chromosomes using probes that emit specific light colour)
what does molecular analysis do?
looks for patterns of gene expression
multiple analyses of patterns of genes that are switched on and off
helps to further classify lymphoma and identify subtypes
how is gene expression profiling used in lymphoma diagnosis?
can show subtypes
i.e different subtypes of diffuse large B cell NHL show different activation markers etc
can show which treatments will work best
how can lymphoma be classified?
hodgkins
T cell non-hodgkins (T-NHL)
B cell non-hodgkins (B-NHL)
- B NHL can be low or high grade
burkitts lymphoma is what type?
B NHL
