Lymphadenopathy Flashcards
Define: lymphadenomegaly
lymph node enlargement
Define: lymphadenopathy
any abnormality of lymph node(s)
- size, shape, structure, cellular composition, necrosis
Define: lymphadenitis
inflammation of lymph nodes
What factors indicate an enlarged and/or pathological lymph node?
see it easily palpate it measurable size is increased, short axis more important - short axis >10mm - long axis >15mm - cross-section area >2.25cm^2
How should you measure a lymph node?
measure with a rule or use US
express results in mm or cm
long axis/short axis ratio is important
- reactive node: usually about 2:1 or higher
- closer to 1:1 (round node) - more likely malignant (sobiaiti index)
(submandibular, parotid and mesenteric lymph nodes may be normally round)
What are the different types of lymphadenomegaly?
localised: one LN / one LN region
regional: 2 or more contiguous regions
Generalised: 2 or more non-contiguous regions
- about 25% lymphadenopathies
What causes lymph node enlargement?
1) in situ proliferation of leukocytes (mostly lymphocytes, but also histiocytes and rarely, dendritic cells)
2) influx of lymphocytes from blood and lymph
3) infiltration by neoplastic cells
4) accumulation of abnormal substances of foreign or endogenous origin, usually phagocytosed by histiocytes
rarely:
- swelling due to necrosis or dilatation of sinuses
- suppuration
Can new LNs arise?
it has been suggested that they can originate “de novo” from clusters of lymphocytes in many sites
What should you do after noting an enlarged lymph node?
enlargement of unknown origin should NOT be treated it MUST be diagnosed
- the exception to this is if it is life threatening obstruction of upper airways by pharyngeal nodes
Should a biopsy of an enlarged LN be performed?
simple algorithmic approach is NOT possible
need to weight up pros and cons
- LN excision biopsy provides plenty info and often definite diagnosis - surgical procedure is costly and although simple it has risks (scar, nerve damage, infection, haemotoma)
What are the chances of an enlarged LN being malignant?
annual incidence of lympahdenopathy in gen pop - 0.6%
What to ask in the history?
history:
- Fam = previous cancers, immunodeficiencies, other cancer RF, TB
- Occupational = contact with animals and animal products, healthcare workers
- Ethnic origin and travel - TB, HTLV1, kikuchi lymphdenitis
- Lifestyle risks= smoking
- Co-morbidities = immunosuppression, current cancer, other autoimmunedisease, RA)
- drugs = anticonvulsants (phenytoin, captopril, mephenytoin)
What can all immunosuppresive agents cause?
e.g. methotrexate administered for RA
may cause lymphoma like growths and true lymphomas
What are the definitions of localised/region LNs and generalised?
localised- focus on drainage area
generalised = serological / haematological tests may give more useful info
- much higher risk of malignancy
What are some non-malignant conditions in which there is generalised LN enlargement?
HIV/AIDs Infectious mononucleosis SLE TB Sarcoidosis
What are the associated symptoms that increase risk of malignancy?
B symptoms
- fever >38
- drenching night sweats
- unexplained weight loss of more than 10% body weight
unexplained generalised pruritus
immunosuppression
unexplained skin rash, particularly when accompanied by oedema, fluid accumulation in body cavities or arthralgias
What is LN pain following alcohol consumption characteristic of?
hodgkin’s lymphoma - rare
What are some worrisome features of enlarged LNs?
likely malignant if:
- lower neck nodes
- abdominal nodes
- fixed to surrounding tissue
- forming aggregates
- painless
- rock hard
- very large 3-4cm
- on imaging:-round, fatty hilum not discernible. necrosis
What is a poor predictor of malignancy and what is a good one?
poor- time
- some say <4 weeks and greater than 1 yr likely to be benign however indolent lymphomas are frequently >1 yr
Age
<30 mostly benign
>50 much more likely to be malignant
What is non-TB mycobacterial infection in children?
1 in 100,000 children per year 80% <5 yrs previously healthy no immunodeficiency isolated unilateral cervical lymphadenitis painless asymptomatic no dissemination IGRA test usually negative
No consensus on treatment (excision, drugs, watch and wait)
RF largely unknown
no human to human transmission
What is the lymph node that drains the thorax, GIT and GU tract and what happens if its enlarged?
supraclavicular
- normally not palpable
over 50% are malignant
- hodgkin’s lymphoma, NHL, bronchial cancer, breast cancer
What is virchow’s node?
left supraclavicular - more frequently malignant than the right, frequently signifies an inoperable malignancy of the git
What is likely if the infraclavicular node is enlarged?
very rare, highly suspicious of hodgkin’s lymphoma
What are some potential diagnoses if the mediastinal LN is enlarged and what can it lead to?
sarcoidosis (rarely massive)
lymphoma (usually massive)]
TB
Can result in superior vena cava syndrome
What are the symptoms of vena cava syndrome?
headache upper thorax /arm congestion turgor of jugular veins dilated superficial chest vein also - dry cough, predominantly expiratory dyspnoea, hiccup
What are the potential causes of enlarged axillary node?
skin infection breast cancer cat-scratch disease melanoma lymphoma silicone leak tattoo reaction - persistent painless anxillary LN
What does the inguinal LN drain and what are the potential diagnoses if its enlarged?
drains penis, scrotum, vulva, anus, perineum, inner thigh, lower abdominal wall (doesnt drain testes)
cellulitis venereal diseases lymphomas melanoma SCC
What are you worried about if you have enlarged abdominal LN?
always highly suspicious of malignancy
even if 1-1.5cm
What does the epitrochlear LN drain and what are you worried about if its enlarged?
medial arm, above medial epicondyle of the humerus often forgotten on physical examination
always pathological regardless of size
frequently malignant if no obvious pathology in the draining area
bilateral enlargement may signify a systemic inflammatory disease - infectious mononucleosis, sarcoidosis, syphilis, tularamia, exotic infections
What are some examples of non-neoplastic conditions in which the LN may be very large?
dermatopathic lymphadenopathy silicone reaction progressive transformation of germinal centres HIV lympahdenitis TB
Also typically painless and therefore makes you think lymphoma
What is dermatopathic lymphadenitis?
LN reaction to any cutaneous changes in the draining area may be disproportional to intensity of skin changes
What is progressive transformation of germinal centres?
abnormal immune reaction, cause unknown but linked to autoimmune phenomena/disorders in 1/4 of patients
self limiting, no treatment needed, may recur
What are some examples of non-neoplastic diseases with lymphoma like clinical presentation?
infectious mononucleosis
kikuchi’s lymphadenitis
SLE
HIV/AIDs
What is kikuchi’s lymphadenitis?
kikuchi-fujimoto disease, necrotising histiocytic lymphadenitis
self-limiting (1-5 months) inflammatory disorder of unknown aetiology
LN are often painful unlike in lymphoma
commonly mis-diagnosed as lymphoma
What do most T cell lymphomas express?
CD4 not CD8
What laboratory investigations are most important with an enlarged LN?
FBC with WBC differential check LDH - if raised strongly suggestive of malignancy throat culture monospot test (infectiousmononucleosis\) HIV test TB skin test autoimmune scan serum total proteins and protein electrophoresis serum markers of germ cell neoplasia
What radiological examinations are helpful?
US
- precise measurements (short axis)
- relationship to contiguous structures
- margins
- presence of other non-palpable nodes in vicinity
- method of choice of superficial LNs
CXR
CT
- generalised LN
- supraclavicular
- any LN with splenomegaly
What should you do if you have localised/regional LN enlarged with high risk of malignancy?
biopsy
What should you do if you have localised/regional LN enlarged with low risk of malignancy?
3-4 week observations
What should you do if you have generalised LN enlarged ?
if still no clear clue from FBC, infectious serology and autoimmune scan then BIOPSY
What are the different types of biopsy?
excision biopsy- best
if not possible then
core needle biopsy or incision biopsy
always target most abnormal/largest node not most easily accessible
Why is the core needle biopsy becoming increasingly popular?
safer
cheaper
quicker
but less accurate
Why is fine needle biopsy not used?
not robust method for diagnosis of lymphadenopathy
cant demonstrate tissue architecture
very little material for special studies
some very good samples can allow flow cytometry, genetics and immunicytochemistry
What is FNA good for?
staging or re-stagin of already diagnosed non-lymphoid cancer
salivary , thyroid, breast, hepatic and pancreatic lesion
LN in cases with high index suspicion for non-lymphoid cancer particularly carcinomas
What can you do with a tissue biopsy?
FISH
Molecular studies
Flow cytometry
touch imprints - quick cytology
