Lymph Flashcards
Describe the normal function and anatomy of lymph nodes
- Normal lymphoid tissue= muscosa of gut, salivary glands and resp tract
- Haemopoeitic system= lymph nodes spleen bone marrow
- Has a cortex with primary and secondary follicles containing B cells
- Medulla has lymph sinuses blood vessels and b cell components
- Lymph carries antigens from afferent lymphatic to intranodal sinuses to exit via efferent lymphatic into medulla
- T cells found in follicles in medulla for cell mediated response -
Describe the features and causes of lymphadenopathy
- In response to an antigen or can be caused by lymphoma/ metastatic cancer
- Can be localised or generalised
Causes
Infectious disease - Viral : Infectious mononucleosis , hepatitis, HIV, measles, rubella
-Bacterial: Streptococci, Brucellois, TB, Syphilis
-Fungal: Histoplasmosis, cryptococcosis
-Chlamydia:
-Parasitic : Toxoplasmosis
Immune disorders: RA, SLE, primary biliary cirrhosis, Drug hypersensitivity, graft vs host disease
Malignancy
Others: Sarcoid, dermatopathic lymphadenitis
What investigations would you conduct in lymphadenopathy
- General examination of all lymph nodes and ENT examination
- Full blood picture
- Serology - EBV, CMV, HIV, Toxoplasma, ANA , Anti ds DNA
- CXR, USS, CT MRI, PET - size and extent of lymph node enlargement and organ abnormalities
- Fine needle aspiration cytology and biopsy
What are some non-neoplastic conditions that can cause lymphadenopathy
- Hyperplasia
- Acute non-specific lymphadenitis- staph infection, typhoid, anthrax
- Chronic non-specific lymphadenitis
- Granulomatous inflammation - sarcoid, TB, fungal infection , Hodgkin’s, Crohns
Describe the features of infectious mononucleosis
- Young adults and children
- Fever, sore throat, lymphadenopathy, splenomegaly
- Monospot test serology: Anti EBV antibodies
- Peripheral blood: Atypical lymphocytes
- Biopsied only when clinical features are atypical/ suspicious of malignancy
- Follicular and sinus hyperplasia with plasma cells and immunoblasts
Describe the features of sarcoidosis
- Common in scandainavia and african americans
- Non specific clinical features
- Can involve any organ most common= lungs, lymph nodes, eyes ,skin, liver
- Histology shows: Non-caseating granulomata, eputhelioid cells, Lanhhan’s giant cells and lymphocytes. Asteroid bodies - calcified structures
- Will have raise ACE and serum calcium
What is the difference between lymphoma and leukaemia
- Lymphoma- solid tumour - nodules or localised masses
- Leukaemi- liquid tumour- systemic and diffuse at outset- mainly based in bone marrow and can evolve in lymph nodes
Discuss the features of Hogkin’s lymphoma
- 2 diseases - classical hodgkin lymphoma, and nodular lymphocyte predominant hodgkin lymphoma
- These 2 diseases have different RS cells, different clinical presentation and different site involvement
What are the more aggressive vs indolent forms of non-hodgkins lymphoma
Indolent
- Lymphocytic lymphoma (B)
- Follicular lymphoma (B)
- Longer survival
Aggressive
- Lymphoblastic lymphoma (B or T)
- Burkitt’s lymphoma (B)
- Diffuse large B-cell lymphoma (B)
- Mantle cell lymphoma (B)
- More chance of cure
Describe the molecular pathology behind lymphomas
- Lymphomas come from a single cell and are clonal proliferations with either antigen receptor (T cell) or immunoglobulin (B cell) gene rearrangements
- B non hodgkins lymphoma is far more common
Describe the features of Chronic lymphocytic leukaemia / small lymphocytic lymphoma
- Commonest leukaemia
- Usually around 60 yrs and more common in males
- Asymptomatic
- Lymphadenopathy and hepatosplenomegaly
- Autoimmune abnormalities: Hypogammaglobulinaemia, thrombocytopenia and haemolytic anaemia
- Morphology: Small lymphocytes, tumour cells stain with CD5 and pan B markers
- Trisomy 12 del 13q
- Absolute lymphocytosis (increased lymphocytes on FBC
Describe the features of follicular lymphoma
- 45% adult NH lymphomas
- Painless lymphadenopathy, lndolent disease, middle aged
- Involves speen, BM and liver
- Tumour B cells called centoblasts and centrocytes express CD10 and bca2 and pan B markers
- Molecular abnormality- t14;18- blocks apoptosis so increased cell survival
Describe the features of mantle cell lymphoma
- Made of small cells but aggressive
- Involvement of peripheral blood, bone marrow, lymph nodes and spleen
- Rarer form of NHL
- GI involvement forms polyps
- Generalised enlarged lymph nodes and spleen
- Proliferation of small lymphoid cells that stain with pan B, CD5 and cyclin D1
- T (11:14) leading to expression of cyclin D1
- Poor prognosis
Describe the features of Burkitt’s lymphoma
- HIV associated
- Can present as leukaemia or lymphoma - nodal or extra nodal abdominal disease
- Children young adults with jawbone mass, ilieocaecal mass
- Intermediate cells with rapid division and macrophages- very high turnover - stain with pan B, CD10 and surface IgM
- Cured with high dose aggressive chemo
Describe the features of diffuse large B cell lymphoma
Aggressive
Any age
large b cells, diffuse growth pattern and express pan B antigens
T(14:18) or Bcl6 gene abnormality
-Speical types are AIDS related or body cavity based d
Describe the features of T cell lymphoma
- Less common and more aggressive
- Worse than B cell NHL
- Lymphadenopathy , skin rash, pruritits , weight loss , fever
- All tumours will show T cell receptor rearrangement and express pan T(CD3 and CD2)
- Types of T cell lymphoma: Mycosis fungicides, peripheral TCL
Describe the features of Hodgkin’s lymphoma
Reed sternberg cells= classical
- 2 types- Nodular lymphocyte predominant HL (stain with CD 20 and B cell markers) and classical HL (stain with CD15 and CD30)
- Most are B cell lymphomas but don’t all express B cell markers
Describe the features of classical hodgkins lymphoma
4 variants that all stain with CD15 and CD30
- Nodular sclerosis: Young adults and women- lower cervical, supraclavicular and mediastinal lymph nodes - very good prognosis- lacunar RS cells and sclerotic bands
- Mixed cellularity- heterogeneous cellular infiltrate- overall good prognosis class RS cells
3, Lymphocyte rich- Isolated cervical or axillary lymphadenopathy - very good prognosis RS cells that remember histiocytes
- Lymphocyte depleted- poorer prognosis higher stage in older men
How is Hodgkins / non Hodgkins nodes staged
-Ann Arbor staging system
Stage 1 - A single lymph node, region or organ
Stage 2- 2 or more LN regions on the same side of the diaphragm
Stage 3- Both sides of diaphragm affects +/- the spleen or extra lymphatic organ
Stage 4- Disseminated disease and bone marrow involvement
A- absence of constitutional symptoms
B-presence of constiutional symptoms - fever night sweats weight loss
Discuss the factors of acute lymphoblastic leukaemia
Children and young adults
Most have blood and bone marrow involvement- bone marrow pain and failure - Pre b cells
Adolescent boys with mediastinal mass- Pre T cells
Blast cells on morphology
Translocations of t12:21, t9;22 and more
Abrupt onset, marrow failure, bone pain , LN testes and CNS involved
Describe the features of myeloma
- Tumour of plasma cells
- Older adults - presentation= bone infiltration, pathological fractures, pain, hypercalcaemia
- Immunosupression and infection
- Excess production and immunoglobulins - renal failure and amyloidosis
- Bone marrow replacement- anaemia, thrombocytopenia, leukopenia
- Morphology: Sheets or mature and immature plasma cells in bone marrow
- Urine will show Bence-jones proteins, M component (IgG or IgA) decreased normal immunoglobulins
