Lymphadenopathy and Lymphoma Flashcards
What is the DDx of lymphadenopathy?
Reactive: Bacterial infection (regional) Viral (generalised) Metastases Lymphoma
Describe viral lymphadenopathy
Tender Hard Smooth No skin inflammation Not tethered
Describe bacterial lymphadenopathy
Tender Hard Smooth Skin Inflammation Maybe tethered
Describe lymphoma lymphadenopathy
Not tender Rubbery/soft Smooth No skin inflammation Not tethered
Describe metastatic lymphadenopathy
Not tender Hard Irregular surface No skin inflammation Tethered
If lymphoma or other malignancy is suspected, what should be done?
Biopsy
FNA or core is often insufficient, large sample needed
Can lymphoma be diagnosed by CT?
No
How is LN histology assessed?
Appreciation of architecture
Whole node sample preferred to CT guided biopsy
How is LN immunohistochemistry assessed?
Confirming lymphoma, helping to subclassify
Surface proteins
Use Antibodies against these, and enzyme reaction. Brown= +ve
Cluster of Designation (CD) numbers
How is immunophenotyping carried out?
Use cells in liquid phase- blood/marrow
Cells are tagged with Abs attached to fluorochrome- emits specific colour of light when laser shone on it
Determine pattern of CD numbers
Useful in leukaemias, and lymphomas involving marrow e.g. Burkitt’s
What is cytogenic analysis used for?
Specific patterns of chromosome abnormality in certain lymphomas
G banding- aspirate node, grow cells in culture and look at chromosome spread
FISH
What is molecular analysis used for?
Patterns of gene expression
Multiple analyses looking at patterns of genes that are switched on and off
Helping to further classify lymphoma and identify subtypes for treatment
What is an example of gene expression profiling and lymphoma?
Diffuse large B cell NHL - activated B cell type shows overexpression of activation markers, responds well to Ibrutinib (inhibitor of cell signalling pathway)
Demonstrated that Reed Sternberg cells in Hodgkin’s were very abnormal B cells that had lost normal proteins eg CD 20
What are the classes of B-NHL?
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; including splenic (SLVL) and extranodal (MALToma)
What are the classes 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
