Approach to the Diagnosis of Lymphadenopathy and Diagnosing Lymphoma Flashcards
(21 cards)
Causes of lymphadenopathy (lump)?
Lymphoma
Infection:
• Viral
• Bacterial
Metastatic cancer, e.g: breast, ovarian
CT disease, e.g: sarcoidosis, SLE
General symptoms that may be assoc. with lymphadenopathy and potential causes of these?
Night sweats: • Lymphoma • Infection • Menopause • Very thick duvet or high central heating
Itch without rash:
• Lymphoma
Alcohol-induced pain:
• Lymphoma - alcohol causing pain in enlarged glands is very characteristic
Fatigue
Differential diagnosis of lymphadenopathy?
Reactive - lymph node is enlarged as an appropriate response, e.g: to infection:
• Bacterial infection - causes a regional lymphadenopathy, e.g: ingrown toenails and cellulitis can cause inguinal lymphadenopathy
• Viral infection - causes a generalised lymphadenopathy, e.g: glandular fever (EBV) causes lymphadenopathy and tonsillitis
Metastatic malignancy - to draining lymph nodes of, e.g: breast, lung
Lymphoma
Approach to lymphadenopathy?
Is it a regional lymphadenopathy?
Is there generalised lymphadenopathy?
Compare the features of lymph nodes in viral infection, bacterial infection, lymphoma and metastatic carcinoma?
Viral infection: • Tender - yes • Consistency - hard • Surface - smooth • Skin inflamed - no • Tethered - no
Bacterial infection: • Tender - yes • Consistency - hard • Surface - smooth • Skin inflamed - yes • Tethered - maybe
Lymphoma: • Tender - no • Consistency - RUBBERY/SOFT • Surface - smooth • Skin inflamed - no • Tethered - no
Metastatic carcinoma: • Tender - no • Consistency - hard • Surface - irregular • Skin inflamed - no • Tethered - yes
NOTE - with infections, the lymph node rapidly grows in size, so the capsule stretching causes pain
If lymphoma or other malignancy is suspected, what Ix should be considered?
Ask a surgeon to biopsy; an FNA or core biopsy is often insufficient and a larger sample is often required to assess the architecture of the lesion
Why can lymphoma not be diagnosed on a CT scan?
It is not a radiological diagnosis, as enlarged lymph nodes are the appearance, which can be caused by lymphoma, metastases, etc
Uses of lymph node biopsy??
Exclude other causes of lymphadenopathy, e.g: reactive
Classification of lymphoma guides treatment and predicts behaviour
Understand the pathogenesis
Methods used to assess lymph node pathology?
Histology
Immunohistochemistry of a solid node
Immunophenotyping of the blood/marrow
Genetic analysis
Molecular analysis
Use of histology?
Microscopic appearance may be enough to make the diagnosis, e.g: nodular sclerosis (nodules surrounded by bands of fibrosis/sclerosis) with Hodgkin’s disease
Whole node biopsy sample is preferred to CT-guided biopsy
Use of immunohistochemistry?
Looks at the pattern of proteins (CD numbers) expressed on lymphoma cells, using antibodies against them
CD - Cluster of Designation numbers
Examples of proteins found on different lymphoma cells?
CD20 +ve cells in follicular NHL
CD30 +ve Reed Sternberg cells in Hodgkin’s disease
Use of immunophenotyping?
Uses cells in the liquid phase, e.g: blood or bone marrow
Cells are tagged with Abs attached to a fluorochrome, which emits a specific light colour when hit with a laser; this allow determination of the pattern of CD numbers
Very useful for leukaemias and lymphomas inv. the bone marrow, e.g: Burkitt’s lymphoma
Use of cytogenetics?
Look for specific patterns of chromosomal abnormalities in certain lymphomas:
• G banding - aspirate lymph node, grow the cells in culture and look at the spread of chromosomes
• FISH (fluorescent in-situ hybridisation) - look for specific abnormalities in chromosomes, using probes that emit a specific light colour
Examples of abnormalities identified with cytogenetics?
T(14:18) - a translocation found in follicular NHL
T(11:14) - a translocation found in mantle cell NHL
Use of molecular analysis?
Look at patterns of gene expression, to see if they are switched on or off
Helps to further classify the lymphoma and identify sub-types suitable for specific treatment
Gene expression profiling of different sub-types of large B cell NHL?
Activated B cells type shows over-expression of activation markers; it responds part. well to Ibrutibin, which inhibits the cell signalling pathway (transducer proteins)
Reed Sternberg cells in Hodgkin’s disease were very abnormal B cells that had lost the normal proteins assoc. with B cells, e.g: CD20
Types of B-NHL? (B cell Non-Hodgkin’s Lymphoma)?
Precursor B-ALL
B-ALL, lymphoblastic NHL
Burkitt’s
DLCL
Mediastinal DLCL
Primary Effusion Lymphoma
Mantle cell lymphoma
Follicular lymphoma
B-CLL, B-PLL, small lymphocytic lymphoma
Lymphoplasmacytic lymphoma
Marginal cell lymphoma, inc. splenic (SLVL) and extranodal (MALToma)
NOTE - the top of this list has the very aggressive cells that grow rapidly; the bottom has more mature cells that grow slowly
Types of T-NHL?
Precursor T-ALL, lymphoblastic lymphoma
T-PLL
T-cell LGL ; NK cell leukaemia / lymphoma
ATLL (HTLV-1+)
CTCL (Sezary / Mycosis Fungoides)
Hepatosplenic gamma / delta cell lymphoma
Enteropathy type T-cell NHL
ALCL
Peripheral T-cell lymphoma
Angioimmunoblastic NHL
Simplifying the classifications of lymphoma?
There are 3 broad categories of lymphoma
- Hodgkin’s
- T cell NHL (10%)
- B-cell NHL (90%):
• Low-grade B cells - persist for many years and are incurable; patient can enter remission following treatment but will inevitably relapse
• High-grade B cell - potentially curable
Specific types of B cell NHL?
Burkitt’s lymphoma
Mantle cell lymphoma - appears low-grade but is very aggressive and has a poor prognosis (incurable)
Marginal zone lymphoma - grow very slowly and often require no treatment
