Lymph Node Pathology Flashcards
The lymphoid follicles
B cells predominantly
Primary follicles- naive b cells
Secondary- germinal center
Paracortex consists mostly of
T cells with scattered B cells
Lymphadenopathy is generally due to
Reactive causes
Neoplastic causes
Reactive lymphadenopathy
*Benign
*Due to inflammation or infection
*Preservation of lymph nodes architecture
Patterns of reactive lymphadenopathy
Follicular hyperplasia (hiv, syphillis)
Sinus hyperplasia (sinus histiocytosis, rossi dorfman disease)
Granulomatous lymphadenitis (tb, sarcoidosis)
Neoplastic lymph…
Malignant
Due to lymphomas or metastases
Partial or complete effacement of lymph node architecture
What are lymphomas?
A general term for a group of blood cancers that originate in the lymphatic system
Hodgkin’s lymphoma
Localised or disseminated malignant proliferation of cells of the lymphoreticular system
Bimodal peak age incidence of 15-35years and >55years
Lymph node involved in a contiguous pattern
Painless lymphadenopathy , constitutional symptoms, pruritus.
Morphological variants of Hl (classical hodgkins)
Nodular sclerosis
Lymphocyte rich
Lymphocyte depleted
Mixed cellularity
Non classical hodgkins lymphoma
Nodular Lymphocyte predominant hodgkin’s lymphoma (NLPHL)
Reed sternberg cell
Large binucleate cell with vesicular nuclei, large prominent pink nucleoli and abundant eosinophil cytoplasm
Other variants of rs cells ie Hodgkin cells
Mononuclear cells seen in all variants
Lacunae cells - typically has a space around them, seen in nodular sclerosing
L&H pop corn cells seen in NLPHL
Positive and negative cd markers for hodgkin’s
Positive for cd30, cd15 and pax5
But negative for cd45
However, excludes pop corn cells which is negative for cd30, cd15 but Positive for cd45 and cd 20.
Thus non classical
Non hodgkin’s lymphoma
Affects all age groups
Non contiguous pattern
Burkitts lymphoma
B cell nhl
Starry sky appearance
Tingled body macrophages
Sea of intermediate lymphocytes
Ebv
t(2,8) t(8,14) t8,22)
Follicular lymphoma
t(14,18)
Indolent
Follicles of same size unlike follicular Hyperplasia
Mantle cell lymphona
t(11,14)
Marginal zone lymphomas and MALT lymphomas
H.pylori- chronic inflammation
t(11,18)
Diffuse large b cell lymphomas
Most common
Aggressive
Adult T-cell lymphoma (leukemia)
Caused by human t-cell dystrophic virus
Which circulates in the body fluids and causes mutation of T-cell DNA to viral DNA
Mycosis fungoides
Skin patches that resemble fungal infection
CD4+ helper T-cell
Microscopically, cerebriform nucleus that looks like a brain
Sezary syndrome -itchy rash(erythroderma)
Angioimmunoblastic lymphoma
Anaplastic large cell lymphoma
Note that T cell lymphomas tend to be generally more aggressive
Metastasis
Carcinomas arising from different sites can metastasize to lymph nodes more frequently than melanomas and sarcomas
B cell non hodgkin’s lymphoma
Be- Burkitts lymphoma
Fr- follicular lymphoma (14,18
My- marginal zone and malt lymphomas-t(11,18)
Man- Mantle cell lymphoma t(11,14)
Sucks- Small lymphocytic lymphoma
D- Diffuse large cell lymohoma
